CN113237032B

CN113237032B - Light source device and lighting device

Info

Publication number: CN113237032B
Application number: CN202110581585.0A
Authority: CN
Inventors: 山中一彦; 春日井秀纪
Original assignee: Nuvoton Technology Corp Japan
Current assignee: Nuvoton Technology Corp Japan
Priority date: 2016-05-13
Filing date: 2017-04-27
Publication date: 2024-01-05
Anticipated expiration: 2037-04-27
Also published as: JPWO2017195620A1; CN113237032A; JP7072037B2; WO2017195620A1; EP3457021B1; US20190097095A1; CN109154425A; EP3457021A1; JP6800221B2; US20210278053A1; CN109154425B; US11028988B2; JP2021028915A; EP3457021A4

Abstract

A light source device (100) is provided with a semiconductor light emitting device (10) which emits coherent excitation light (81), and a wavelength conversion element (30) which is arranged to be separated from the semiconductor light emitting device (10) and to convert the wavelength of the excitation light (81) emitted from the semiconductor light emitting device (10) to generate fluorescence (94) and scatter the excitation light (81) to generate scattered light (93), wherein the wavelength conversion element (30) is provided with a support member (32) and a wavelength conversion section (38) arranged on the support member (32), the wavelength conversion section (38) is provided with a first wavelength conversion section (35), and a second wavelength conversion section (36) which is arranged around the first wavelength conversion section (35) when the surface of the support member (32) on which the wavelength conversion section (38) is arranged is viewed in plan, and the intensity ratio of the fluorescence (94) to the scattered light (93) is lower than that of the first wavelength conversion section (35).

Description

Light source device and lighting device

The present application is a divisional application of the invention patent application having a filing date of 2017, 04, 27, a filing number of 201780028318.2 and a name of "light source device and lighting device".

Technical Field

The present disclosure relates to a light source device and a lighting device.

Background

Conventionally, a light source device using a semiconductor light emitting device and a wavelength conversion element has been proposed (for example, see patent document 1). As for such a light source device, a light source device disclosed in patent document 1 will be described with reference to fig. 39. Fig. 39 is a schematic diagram of a conventional light source device. Fig. 39 shows a cross-sectional view (a) and a plan view (b) of a conventional light source device 1020.

As shown in a cross-sectional view (a) of fig. 39, the light source device 1020 disclosed in patent document 1 includes: a semiconductor light emitting device 1005 that emits excitation light having a predetermined wavelength from among a wavelength range of ultraviolet light to visible light; a phosphor layer 1002 into which excitation light from the semiconductor light emitting device 1005 enters; and a light reflective substrate 1006 provided on a surface opposite to a surface on which excitation light is incident, of the surfaces of the phosphor layer 1002.

Here, the phosphor layer 1002 is fixed to the light-reflective substrate 1006 by a joint 1007.

The semiconductor light emitting device 1005 and the phosphor layer 1002 are configured as a spatially separated reflective light source device 1020.

The phosphor layer 1002 contains a phosphor that is excited by excitation light from the semiconductor light emitting device 1005 and emits fluorescence having a longer wavelength than the wavelength of the excitation light.

Further, around the phosphor layer 1002, an absorption means 1009 that absorbs excitation light from the semiconductor light emitting device 1005 when the excitation light is incident, or a scattering means that scatters (diffuses) the excitation light are provided.

The cross-sectional shape and cross-sectional area of the light beam incident on the phosphor layer incident surface of the excitation light from the semiconductor light emitting device 1005 incident on the phosphor layer 1002 are substantially the same as the shape and area of the entire incident surface to the phosphor layer.

According to this structure, it is proposed to prevent color unevenness in the light emitting points (light emitting patterns) of the phosphor layer 1002.

(prior art literature)

(patent literature)

Patent document 1: japanese patent application laid-open No. 2012-89316

In the light source device 1020 disclosed in patent document 1, when the absorption unit 1009 is disposed around, a part of the excitation light enters the absorption unit 1009. The fluorescence emitted from the side surface of the phosphor layer 1002, that is, the surface of the phosphor layer 1002 in contact with the absorber 1009, among the light emitted from the phosphor layer 1002, enters the absorber 1009. As a result, excitation light and fluorescence are absorbed by the absorption unit 1009 in the absorption unit 1009, and the light emission efficiency of the light source device is reduced.

When scattering means is arranged in place of the absorption means 1009 around the phosphor layer 1002, excitation light incident on the scattering means is scattered on the surface of the scattering means and emitted. As a result, excitation light is emitted from the peripheral region of the light-emitting region of the light source device 1020 without mixing with fluorescence. When such light source device is projected to form an image, blue light of excitation light is projected in a ring shape around a white region in the center. Such a phenomenon occurs even when the absorption units 1009 are disposed around the phosphor layer 1002. This is because, as the absorbing means 1009, there is no inexpensive material that absorbs 100% of the excitation light.

When such a light source device is used for an illumination device, it is difficult to control the color distribution of the entire projected image.

Disclosure of Invention

Accordingly, an object of the present disclosure is to provide a light source device which has high efficiency of using excitation light and can freely design a projection image and illuminance distribution and color distribution around the projection image, and an illumination device using the light source device.

In order to achieve the above object, the present disclosure provides a light source device including a semiconductor light emitting device that emits coherent excitation light, and a wavelength conversion element that is disposed so as to be separated from the semiconductor light emitting device, performs wavelength conversion on the excitation light emitted from the semiconductor light emitting device to generate fluorescence, and scatters the excitation light to generate scattered light, the light source device including a support member, and a wavelength conversion portion disposed on the support member, the wavelength conversion portion including a first wavelength conversion portion and a second wavelength conversion portion, the second wavelength conversion portion being disposed around the first wavelength conversion portion when viewed in plan on a surface of the support member on which the wavelength conversion portion is disposed, the second wavelength conversion portion being lower than the first wavelength conversion portion with respect to an intensity ratio of the fluorescence to the scattered light.

According to the above configuration, since the second wavelength converting region is disposed around the first wavelength converting region, the luminance and spectrum of the light emitted from the second wavelength converting region can be freely designed by appropriately adjusting the configuration of the second wavelength converting region. Therefore, in the light source device, when the light emission region is formed by mainly irradiating the first wavelength conversion portion with the excitation light, it is possible to suppress emission of only the excitation light from the peripheral region of the light emission region. Further, the light emitting region and the luminance distribution and the color distribution around the light emitting region can be freely designed. Therefore, the projection image and the illuminance distribution and the color distribution around the projection image can be freely designed. Further, according to the above configuration, the loss of excitation light and fluorescence can be suppressed as compared with the case where the absorption means is arranged instead of the second wavelength converting portion. That is, the utilization efficiency of the excitation light can be improved.

Further, in the light source device according to the present disclosure, the first wavelength conversion unit may have a second surface facing the support member, a first surface facing away from the second surface, and a side surface connecting the first surface and the second surface, and the wavelength conversion element may include a reflection member covering at least a part of the second surface and the side surface.

According to this configuration, excitation light and fluorescence from the wavelength conversion portion toward the support member can be reflected and utilized as output light. Therefore, the conversion efficiency of the light source device can be improved.

In order to achieve the above object, the present disclosure provides a light source device including a semiconductor light emitting device that emits coherent excitation light, and a wavelength conversion element that is disposed separately from the semiconductor light emitting device, performs wavelength conversion on the excitation light emitted from the semiconductor light emitting device to generate fluorescence, and transmits the excitation light to generate transmission light, the light source device including a support member, and a wavelength conversion portion disposed on the support member, the wavelength conversion portion including a first wavelength conversion portion and a second wavelength conversion portion, the second wavelength conversion portion being disposed around the first wavelength conversion portion, the second wavelength conversion portion being lower than the first wavelength conversion portion with respect to an intensity ratio of the fluorescence to the transmission light when viewed from above on a surface of the support member on which the wavelength conversion portion is disposed.

According to the above configuration, since the second wavelength converting region is disposed around the first wavelength converting region, the luminance and spectrum of the light emitted from the second wavelength converting region can be freely designed by appropriately adjusting the configuration of the second wavelength converting region. Therefore, in the light source device, when the light emission region is formed by mainly irradiating the first wavelength conversion portion with excitation light, emission of excitation light from the periphery of the light emission region can be suppressed. Further, the light emitting region and the luminance distribution and the color distribution around the light emitting region can be freely designed. Further, according to the above configuration, the loss of excitation light and fluorescence can be suppressed as compared with the case where the absorption means is arranged instead of the second wavelength converting portion. That is, the utilization efficiency of the excitation light can be improved.

Further, in the light source device according to the present disclosure, a cross-sectional shape and a cross-sectional area of the excitation light of the incident surface of the first wavelength conversion section on which the excitation light is incident may be substantially the same as a shape and an area of the incident surface of the first wavelength conversion section.

According to the above configuration, the uniformity of the luminance distribution in the central portion of the light-emitting region can be improved, and the emission of excitation light from the periphery of the light-emitting region without mixing with fluorescence can be suppressed.

Further, in the light source device according to the present disclosure, the first wavelength conversion unit may include a first emission region into which the excitation light is incident, and a cross-sectional shape and a cross-sectional area of the excitation light of an incident surface of the first emission region into which the excitation light is incident may be substantially the same as a shape and an area of the incident surface of the first emission region.

Further, in the light source device according to the present disclosure, the first wavelength conversion unit may include a first emission region into which the excitation light is incident and from which the transmission light is emitted, and a cross-sectional shape and a cross-sectional area of the excitation light of an incident surface of the first emission region into which the excitation light is incident may be substantially the same as a shape and an area of the incident surface of the first emission region.

Further, in the light source device according to the present disclosure, the first wavelength conversion portion may be formed of a single phosphor material.

According to the above configuration, in the wavelength converting region, the first wavelength converting region is made of a single material having a uniform refractive index. Therefore, the excitation light is reflected multiple times within the first wavelength converting region, so that the uniformity of the luminance distribution in the central portion of the light emitting region can be improved.

Further, in the light source device according to the present disclosure, the first wavelength conversion portion may include a plurality of air holes.

According to the above configuration, the first wavelength converting region is made of the same material having a uniform refractive index and includes the air holes as the scatterer. Therefore, the excitation light is reflected multiple times in the first wavelength converting region, and the light emission distribution can be suppressed from becoming uneven.

Further, in the light source device according to the present disclosure, the first wavelength conversion portion may include phosphor particles and a transparent binding material.

In this configuration, the first wavelength conversion portion can scatter excitation light at the interface between the phosphor particles and the transparent bonding material, and as a result, the light emission distribution can be suppressed from becoming uneven.

Further, in the light source device according to the present disclosure, the second wavelength converting region may include a phosphor material different from the first wavelength converting region.

According to the above configuration, the conversion efficiency of the second wavelength converting region into fluorescence and the spectrum of the emitted light can be freely designed to be different from those of the first wavelength converting region.

Further, in the light source device according to the present disclosure, the average particle diameter of the phosphor particles included in the second wavelength converting region may be different from the average particle diameter of the phosphor particles included in the first wavelength converting region.

According to the above configuration, the conversion efficiency of the second wavelength converting region into fluorescence can be freely designed to be different from the conversion efficiency of the first wavelength converting region.

Further, in the light source device according to the present disclosure, the volume ratio of the phosphor particles contained in the first wavelength converting region may be different from the volume ratio of the phosphor particles contained in the second wavelength converting region.

The light source device according to the present disclosure includes: a semiconductor light emitting device for emitting laser light; a wavelength conversion member to which laser light emitted from the semiconductor light emitting device is irradiated as excitation light, thereby emitting fluorescence; a first filter into which a part of the light emitted from the wavelength conversion element is incident; a first photodetector for receiving light from the first filter; a second photodetector on which the light emitted from the wavelength conversion element is incident; and a third photodetector on which the excitation light is incident.

According to the above configuration, the light source device can detect the ratio of the amount of scattered light and the amount of fluorescent light of the light emitted from the wavelength conversion element and the ratio of the amount of excitation light and the amount of fluorescent light. Therefore, when the positions of the components constituting the light source device in the light source device deviate during the operation of the light source device, a slight failure state inside the light source device can be detected.

Further, the light source device according to the present disclosure may include a second filter, into which a part of the light emitted from the wavelength conversion element is incident, and the light passing through the second filter may be incident on a second photodetector.

Further, the light source device according to the present disclosure may further include a reflecting member that guides the light emitted from the wavelength conversion element to the first detector.

Further, the light source device according to the present disclosure may further include a reflecting member that guides the light emitted from the wavelength conversion element to the second detector.

Further, the light source device according to the present disclosure may further include a condensing member that condenses and irradiates the laser light emitted from the semiconductor light emitting device to the wavelength conversion element.

Further, in the light source device according to the present disclosure, the first detector, the second detector, and the third detector may be disposed on the same substrate.

The light source device according to the present disclosure includes the light source device.

In the lighting device, the same effect as the light source device can be obtained.

According to the present disclosure, a light source device capable of freely designing a light emitting region and a luminance distribution and a color distribution around the light emitting region while maintaining high conversion efficiency, and a lighting device using the light source device can be provided.

Drawings

Fig. 1 is a schematic cross-sectional view showing a schematic configuration of a light source device according to embodiment 1.

Fig. 2A is a schematic cross-sectional view showing a schematic structure of the wavelength conversion element according to embodiment 1.

Fig. 2B is a schematic perspective view showing a schematic structure of the wavelength conversion element according to embodiment 1.

Fig. 2C is a schematic cross-sectional view showing the function of the wavelength conversion element according to embodiment 1.

Fig. 2D is a schematic partially enlarged cross-sectional view showing an example of the schematic structure of the wavelength conversion element according to embodiment 1.

Fig. 2E is a schematic partially enlarged cross-sectional view showing an example of the schematic structure of the wavelength conversion element according to embodiment 1.

Fig. 2F is a schematic partially enlarged cross-sectional view showing an example of the schematic structure of the wavelength conversion element according to embodiment 1.

Fig. 2G is a schematic partially enlarged cross-sectional view showing an example of the schematic structure of the wavelength conversion element according to embodiment 1.

Fig. 2H is a schematic partially enlarged cross-sectional view showing an example of the schematic structure of the wavelength conversion element according to embodiment 1.

Fig. 2I is a schematic partially enlarged cross-sectional view showing an example of the schematic structure of the wavelength conversion element according to embodiment 1.

Fig. 2J is a schematic partially enlarged cross-sectional view showing an example of the schematic structure of the wavelength conversion element according to embodiment 1.

Fig. 3 is a schematic cross-sectional view for explaining the function of the wavelength conversion element according to embodiment 1.

Fig. 4 is a graph showing schematic luminance distributions of the emission regions of the wavelength conversion element according to example 1 and the wavelength conversion element according to the comparative example.

Fig. 5 is a diagram schematically showing a projection image obtained by an illumination device combining a light source device and a light projecting member according to embodiment 1.

Fig. 6A is a graph showing the spectrum of the emitted light in the first emission region of the light source device according to embodiment 1.

Fig. 6B is a graph showing the spectrum of the light emitted from the second emission region of the light source device according to embodiment 1.

Fig. 6C is a chromaticity diagram showing the color distribution of projection light of the light source device according to embodiment 1.

Fig. 7 is a schematic cross-sectional view showing a schematic configuration of a lighting device using a light source device according to embodiment 1.

Fig. 8 is a schematic cross-sectional view showing a specific structure of a wavelength conversion element of the light source device according to embodiment 1.

Fig. 9A is a schematic cross-sectional view showing a schematic configuration of a wavelength conversion element according to modification 1 of embodiment 1.

Fig. 9B is a schematic cross-sectional view showing a schematic configuration of a wavelength conversion element according to modification 2 of embodiment 1.

Fig. 10A is a schematic cross-sectional view showing a schematic configuration of a wavelength conversion element according to modification 3 of embodiment 1.

Fig. 10B is a schematic cross-sectional view showing a schematic configuration of a wavelength conversion element according to modification 4 of embodiment 1.

Fig. 11 is a chromaticity diagram showing chromaticity coordinates of light emitted from the light source device according to embodiment 2.

Fig. 12 is a diagram illustrating a function of a vehicle using the light source device according to embodiment 2.

Fig. 13 is a schematic cross-sectional view showing the structure and function of a light source device according to a modification of embodiment 2.

Fig. 14 is a diagram illustrating a specific configuration of a wavelength conversion element for a light source device according to a modification of embodiment 2.

Fig. 15 is a schematic cross-sectional view showing a schematic structure of a wavelength conversion element according to embodiment 3.

Fig. 16 is a sectional view showing a more specific structure of a wavelength conversion element for a light source device of embodiment 3.

Fig. 17 is a schematic cross-sectional view showing each step of the method for manufacturing a wavelength conversion element according to embodiment 3.

Fig. 18A is a schematic cross-sectional view showing the structure of a wavelength conversion element according to modification 1 of embodiment 3.

Fig. 18B is a schematic cross-sectional view showing the structure of a wavelength conversion element according to modification 2 of embodiment 3.

Fig. 18C is a schematic cross-sectional view showing the structure of a wavelength conversion element according to modification 3 of embodiment 3.

Fig. 19 is a schematic cross-sectional view showing a schematic configuration of a light source device according to embodiment 4.

Fig. 20 is a block diagram showing the paths of the propagation light from the semiconductor light emitting device, the emission light from the wavelength conversion element, and the signals from the respective photodetectors in the light source device according to embodiment 4.

Fig. 21 is a flowchart showing a flow of signal processing of the light source device according to embodiment 4.

Fig. 22 is a schematic cross-sectional view showing a schematic configuration of a light source device according to modification 1 of embodiment 4.

Fig. 23 is a graph showing an example of measurement of the luminance distribution and the color distribution of the light emitting surface of the light source device according to modification 1 of embodiment 4 and the comparative example.

Fig. 24 is a schematic cross-sectional view showing a schematic configuration of a light source device according to modification 2 of embodiment 4.

Fig. 25 is a schematic cross-sectional view showing a schematic structure of a wavelength conversion element according to embodiment 5.

Fig. 26 is a schematic cross-sectional view showing the function of the wavelength conversion element according to embodiment 5.

Fig. 27 is a schematic cross-sectional view showing a schematic configuration of a wavelength conversion element used in a light source device according to a modification of embodiment 5.

Fig. 28 is a schematic cross-sectional view showing a schematic structure of a wavelength conversion element used for the light source device according to embodiment 6.

Fig. 29 is a schematic cross-sectional view showing each step of the method for manufacturing a wavelength conversion element according to example 6.

Fig. 30 is a schematic cross-sectional view showing a schematic configuration of a wavelength conversion element for a light source device according to modification 1 of embodiment 6.

Fig. 31A is a schematic cross-sectional view showing a schematic configuration of a wavelength conversion element for a light source device according to modification 2 of embodiment 6.

Fig. 31B is a schematic cross-sectional view showing a schematic configuration of a wavelength conversion element for a light source device according to modification 3 of embodiment 6.

Fig. 31C is a schematic cross-sectional view showing a schematic configuration of a wavelength conversion element for a light source device according to modification 4 of embodiment 6.

Fig. 32 is a cross-sectional view schematically showing the schematic structure of a light source device according to embodiment 6.

Fig. 33 is a schematic cross-sectional view showing a schematic configuration of a wavelength conversion element for a light source device according to embodiment 7.

Fig. 34 is a schematic oblique view showing the structure and operation outline of the light source device according to embodiment 7.

Fig. 35 is a schematic cross-sectional view showing a schematic configuration of a wavelength conversion element for a light source device according to a modification of embodiment 7.

Fig. 36 is a schematic cross-sectional view showing the structure and function of the light source device according to embodiment 8.

Fig. 37 is a schematic cross-sectional view showing the structure and function of a light source device according to a modification of embodiment 8.

Fig. 38 is a schematic cross-sectional view showing a specific configuration of the light source device according to a modification of embodiment 8 when the light projecting member is mounted.

Fig. 39 is a schematic diagram of a conventional light source device.

Symbol description

10. Semiconductor light emitting device

11. Semiconductor light emitting device

11a optical waveguide

12. Support member

13. Package body

13a, 13b, 13d pins

14. Metal can

20. Condensing optical system

20a, 20d lens

20b reflective optical element

20c optical fiber

21. Separating optical elements

22. Reflection member

23. First filter

24. Second filter

25. First photodetector

26. Second photodetector

27. Third photodetector

30. 30A, 30B, 30C, 30D, 130, 230A, 230B, 230C, 330A, 430A, 430B, 430C, 430D, 530A wavelength converting element

31. Reflection member

31a surface

32. 32r support member

32a reflective film

32b bottom

32c concavo-convex

33. Reflection preventing film

34. Bonding material

35. First wavelength converting part

35a, 36a first face

35b, 36b second face

35c side

36. Second wavelength conversion part

38. Wavelength conversion unit

39. Adhesive layer

41. A first injection region

42. A second emission region

50. Shell body

51. 52, 61a cover member

53. Support member

54. Retainer

55. 56 screw

57. Second shell

62. Printed circuit board with improved heat dissipation

65. Micro controller

67. Connector with a plurality of connectors

68. External wiring

70. Heat dissipation mechanism

75. Heat dissipation part

81. Exciting light

82. 84, 85 propagating light

82a, 82b

82i center axis

85a incident light

86a, 94a, 94b (wavelength converted light)

91. 92 light emitted

93. 93a, 93b

95. Emitted light

96. Projection light

99. 99a, 99b projection image

100. 101, 102A, 103, 104A, 300, 400, 500 light source device

120. Light projecting component

135c side

150. Vacuum chuck

155. 156 phosphor particles

157. Second particles

158. 456 void space

199. Butt-head vehicle

200. Lighting device

235c side

255. 256 transparent bonding material

299. Vehicle with a vehicle body having a vehicle body support

355. 356 interface

555. Phosphor phase

655. Matrix phase.

Detailed Description

Hereinafter, each embodiment will be described with reference to the drawings. The present disclosure is not limited to the following examples. The numerical values, the constituent elements, the arrangement positions and connection forms of the constituent elements, the steps (steps) and the sequence of the steps, and the like shown in the following examples are examples and are not limiting to the gist of the present disclosure. The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the ratio of the sizes between the parts, and the like are not necessarily the same as those in reality. Even in the case where substantially the same portions are shown, there are cases where the portions are shown in different sizes and ratios according to the drawings. There are cases where duplicate explanation of substantially the same structure is omitted. Among the constituent elements of the following examples, those not described in the embodiments showing the uppermost concepts of the present invention are described as arbitrary constituent elements.

Various modifications of the present embodiment which are within the scope of the modifications as will occur to those skilled in the art without departing from the spirit of the present disclosure are also encompassed within the present disclosure. Also, at least a part of the plurality of embodiments may be combined within a range not departing from the gist of the present disclosure.

In the present specification, the term "upper" is not used to indicate an absolute upward direction of spatial perception (vertically upward), but is used as a term defined by a relative positional relationship based on a lamination order of a laminated structure. The term "above" is not limited to the case where two components are arranged with a space therebetween and other components are present between the two components, but is also applicable to the case where two components are arranged in close contact with each other and the two components are in contact.

Example 1

Hereinafter, a light source device according to embodiment 1 will be described with reference to the drawings.

Fig. 1 is a schematic cross-sectional view showing a schematic configuration of a light source device 100 according to the present embodiment.

As shown in fig. 1, a light source device 100 according to the present embodiment includes a semiconductor light emitting device 10, a condensing optical system 20, and a wavelength conversion element 30.

The semiconductor light emitting device 10 emits coherent excitation light, and includes a semiconductor light emitting element 11.

The semiconductor light emitting element 11 is, for example, a semiconductor laser element (e.g., a laser chip) made of a nitride semiconductor, and emits laser light having a peak wavelength between 380nm and 490nm as excitation light 81. As shown in fig. 1, in the present embodiment, a semiconductor light emitting element 11 is mounted on a support member 12 such as a silicon carbide substrate, and is mounted on a package, not shown.

The semiconductor light emitting element 11 has a structure in which, for example, a first clad layer, a light emitting layer as an InGaN multiple quantum well layer, and a second clad layer are stacked on a substrate as a GaN substrate.

In addition, an optical waveguide 11a is formed in the semiconductor light emitting element 11.

Power is input to the semiconductor light emitting element 11 from outside the light source device 100. The laser light having a peak wavelength of 445nm, for example, generated in the optical waveguide 11a of the semiconductor light emitting element 11 is emitted as excitation light 81 to the condensing optical system 20.

The condensing optical system 20 condenses the excitation light 81 emitted from the semiconductor light emitting element 11. The configuration of the condensing optical system 20 is not particularly limited as long as the excitation light 81 can be condensed. For the condensing optical system 20, for example, one or more convex lenses, more specifically, an optical system combining an aspherical convex lens and a spherical convex lens can be utilized. The condensing optical system 20 condenses the excitation light 81 having an emission angle in the horizontal direction and the vertical direction emitted from the semiconductor light emitting element 11, and generates propagation light 82 that is excitation light that propagates spatially while being collimated or condensed to the wavelength conversion element 30. The propagation light 82 propagates along the central axis 82i and irradiates the wavelength conversion element 30. At this time, the central axis 82i is set to a predetermined angle, preferably an angle of 60 degrees or more and 80 degrees or less from the normal line of the surface of the wavelength conversion element 30 (i.e., the surface on which the propagation light 82 is incident).

The wavelength conversion element 30 is an element that is disposed separately from the semiconductor light emitting device 10, performs wavelength conversion on excitation light emitted from the semiconductor light emitting device 10 to generate fluorescence, and scatters the excitation light to generate scattered light. In the present embodiment, the wavelength conversion element 30 is irradiated with the propagation light 82 as excitation light, at least a part of the propagation light 82 is wavelength-converted, and the wavelength-converted light is emitted. Hereinafter, the wavelength conversion element 30 will be described with reference to fig. 1, and also with reference to fig. 2A, 2B, 2C, 2D, 2E, 2F, 2G, 2H, 2I, and 2J.

Fig. 2A is a schematic cross-sectional view showing a schematic structure of the wavelength conversion element 30 according to the present embodiment. Fig. 2B is a schematic oblique view showing a schematic configuration of the wavelength conversion element 30 according to the present embodiment. Fig. 2C is a schematic cross-sectional view showing the function of the wavelength conversion element 30 according to the present embodiment. Fig. 2D, 2E, 2F, 2G, 2H, 2I, and 2J are schematic partially enlarged cross-sectional views each showing an example of a schematic configuration of the wavelength conversion element 30 according to the present embodiment. Fig. 2D, 2E, 2F, 2G, 2H, 2I, and 2J show enlarged sectional views corresponding to the inside of the dashed box II shown in fig. 2A.

As shown in fig. 1, the propagation light 82 having a predetermined cross-sectional area and a predetermined light distribution, which is emitted from the semiconductor light emitting element 11, is irradiated to the wavelength conversion element 30. As shown in fig. 1 and fig. 2A to 2C, the wavelength conversion element 30 includes a support member 32 and a wavelength conversion portion 38 disposed on the support member 32. The wavelength conversion unit 38 includes a first wavelength conversion unit 35, and a second wavelength conversion unit 36 disposed around the first wavelength conversion unit 35 and surrounding the first wavelength conversion unit when viewed from above on the surface of the support member 32 on which the wavelength conversion unit 38 is disposed. The first wavelength converting region 35 and the second wavelength converting region 36 include a phosphor material activated with a rare earth element. The phosphor material absorbs at least a part of the propagating light 82, and emits fluorescence having a wavelength different from that of the propagating light 82 as wavelength-converted light.

In this embodiment, as shown in fig. 2A and 2C, the first wavelength conversion portion 35 includes a second surface 35b facing the support member 32, a first surface 35a facing away from the second surface 35b, and a side surface 35C connecting the first surface 35a and the second surface 35 b. The wavelength conversion element 30 includes a reflecting member 31 covering at least a part of the second surface 35b and the side surface 35c.

More specifically, as shown in fig. 2B, the wavelength conversion element 30 includes, for example, a plate-shaped support member 32 having a quadrangular outer shape, a reflecting member 31 formed on the support member 32, a first wavelength conversion portion 35, and a second wavelength conversion portion 36. A first wavelength converting region 35 is formed in a central portion of the surface 31a of the reflecting member 31, and a second wavelength converting region 36 is formed around the first wavelength converting region.

The surface of the first wavelength converting region 35 is constituted by the second surface 35b facing the support member 32 (i.e., on the support member 32 side), the first surface 35a facing away from the second surface 35b (i.e., on the opposite side from the support member 32 side), and the side surface 35c connecting the first surface 35a and the second surface 35b, as described above. In the present embodiment, the side surface 35c faces the second wavelength converting region 36.

The surface of the second wavelength converting region 36 also has a second surface 36b facing the support member 32 and a first surface 36a facing away from the second surface 35 b.

In the present embodiment, the first wavelength converting region 35 and the second wavelength converting region 36 are contacted by the side face 35 c.

At this time, the average refractive index of the first wavelength converting region 35 is different from the average refractive index of the second wavelength converting region 36. That is, the average refractive index changes with the side surface 35c as the boundary between the first wavelength converting region 35 and the second wavelength converting region 36.

Here, a more specific configuration of the first wavelength converting region 35 and the second wavelength converting region 36 will be described with reference to fig. 2D, 2E, 2F, 2G, 2H, 2I, and 2J. The first wavelength converting region 35, the second wavelength converting region 36, and the interfaces thereof according to the present embodiment can be realized in a plurality of modes.

First, a first example will be described with reference to fig. 2D. Fig. 2D is an enlarged view of the first wavelength converting region 35 and the second wavelength converting region 36 of the wavelength converting element 30, and the interfaces thereof. The first wavelength converting region 35 includes phosphor particles 155 and a transparent binding material 255, and the second wavelength converting region 36 includes phosphor particles 156 and a transparent binding material 256. Here, the first wavelength converting region 35 is different from the second wavelength converting region 36 with respect to at least one of the phosphor particles and the transparent bonding material. Accordingly, the average refractive index of the first wavelength converting region 35 and the second wavelength converting region 36 is changed by using the side surface 35c as a boundary. The conversion efficiency of the second wavelength converting region 36 into fluorescence can be freely designed to be different from the conversion efficiency of the first wavelength converting region 35.

The first wavelength converting region 35 and the second wavelength converting region 36 may be composed of phosphor particles and a transparent binding material, and the phosphor particles and the transparent binding material constituting the first wavelength converting region 35 may be made of the same materials as those constituting the phosphor particles and the transparent binding material constituting the second wavelength converting region 36, respectively, so that the average particle diameter of the phosphor particles or the volume ratio of the phosphor particles (herein, (volume of phosphor particles)/(volume of phosphor particles+volume of transparent binding material)) as the mixing ratio of the phosphor particles and the transparent binding material is different. For example, as shown in fig. 2E, the phosphor particles 155 and the transparent bonding material 255 of the first wavelength converting region 35 are the same materials as the phosphor particles 156 and the transparent bonding material 256 of the second wavelength converting region 36, respectively. However, the phosphor particles 156 of the second wavelength converting region 36 have a smaller average particle diameter than the phosphor particles 155 of the first wavelength converting region 35. Accordingly, the average refractive index of the first wavelength converting region 35 and the second wavelength converting region 36 is changed by using the side surface 35c as a boundary.

As shown in fig. 2E, the volume ratio of the phosphor particles contained in the first wavelength converting region 35 is smaller than the volume ratio of the phosphor particles contained in the second wavelength converting region 36. Accordingly, the average refractive index of the first wavelength converting region 35 and the second wavelength converting region 36 is changed by using the side surface 35c as a boundary.

In the example shown in fig. 2D and 2E, since the first wavelength converting region 35 includes the phosphor particles 155 and the transparent bonding material 255, excitation light (propagation light 82) can be scattered at the interface between the phosphor particles 155 and the transparent bonding material 255, and as a result, the light emission distribution can be suppressed from becoming uneven. Further, in the example shown in fig. 2D, since the second wavelength converting region 36 includes a phosphor material different from that of the first wavelength converting region 35, the conversion efficiency of the second wavelength converting region into fluorescence and the spectrum of the emitted light can be freely designed to be different from those of the first wavelength converting region.

For example, the first wavelength converting region 35 may be made of only a single phosphor material, and the second wavelength converting region 36 may be made of a mixture of phosphor particles and a transparent binding material. For example, as shown in fig. 2F, the first wavelength converting region 35 is made of a polycrystalline phosphor material composed of a plurality of phosphor particles 155. As a result, the first wavelength converting region 35 serves as a converting region in which the refractive index of the phosphor material is the average refractive index. Accordingly, the average refractive index of the first wavelength converting region 35 and the second wavelength converting region 36 is changed by using the side surface 35c as a boundary.

In addition, the first wavelength converting region 35 made of a single phosphor material may include a plurality of air holes (air holes 455a and intra-particle air holes 455b shown in fig. 2F). Accordingly, the first wavelength converting region 35 can be made of the same uniform material having the refractive index of the phosphor material and include pores as a scatterer. According to the above configuration, the wavelength conversion element 30 having the average refractive index of the first wavelength conversion region 35 in the vicinity of the side surface 35c and the average refractive index of the second wavelength conversion region 36 different from each other can be easily realized.

For example, the first wavelength converting region 35 may be composed of a ceramic composite including a phosphor phase and a matrix phase, and the second wavelength converting region 36 may be composed of a mixture of phosphor particles and a transparent binding material.

For example, in the example shown in fig. 2G and 2H, the first wavelength converting region 35 is constituted by a plurality of phosphor phases 555 and a matrix phase 655.

Accordingly, the average refractive index of the first wavelength converting region 35 and the second wavelength converting region 36 is changed by using the side surface 35c as a boundary. Further, excitation light can be scattered at the interface 355 between the fluorescent body 555 and the matrix 655.

Further, in the first wavelength converting region 35 shown in fig. 2H, a void 456 is provided in the matrix phase 655 or at the interface between the fluorescent body 555 and the matrix phase 655. According to this configuration, the excitation light can be more easily scattered by the first wavelength converting region 35.

For example, the transparent bonding material may contain, in addition to the phosphor particles, the second particles 157 composed of inorganic transparent particles in one or both of the first wavelength converting region 35 and the second wavelength converting region 36. According to this structure, the average refractive index and the light scattering property can be designed more freely in the wavelength converting region.

For example, in fig. 2I, the first wavelength converting region 35 and the second wavelength converting region 36 include the same second particles 157. The first wavelength converting region 35 and the second wavelength converting region 36 have different concentrations of one or both of the phosphor particles 155 and the second particles 157. That is, the ratio of the phosphor particles 155 to the second particles 157 in the wavelength converting region is different. In this case, the phosphor particles 155 and the second particles 157 may be particles having different refractive indices.

According to this configuration, the first wavelength converting region 35 and the second wavelength converting region 36 can be configured to have different average refractive indices.

For example, in fig. 2I, in the second wavelength converting region 36, the density of the second particles 157 is high. According to this configuration, the second wavelength converting region 36 can have a total amount of the interface 355 between the transparent binder and the phosphor particles and the interface 355 between the transparent binder and the second particles larger than that of the first wavelength converting region 35. As a result, reflection of the excitation light can be enhanced at the side surface 35 c.

Further, in the example shown in fig. 2J, the first wavelength converting region 35 and the second wavelength converting region 36 include a void 158. The first wavelength converting region 35 is different from the second wavelength converting region 36 in terms of the ratio of the volume of the void 158 in the volume of the wavelength converting region. Accordingly, the first wavelength converting region 35 and the second wavelength converting region 36 can have different average refractive indices. Further, the first wavelength converting region 35 is different from the second wavelength converting region 36 with respect to the total area of the void 158 and the interface 355 with any one of the transparent bonding material 255, the phosphor particles 155, or the second particles 157. Therefore, the scattering degree of the excitation light inside the wavelength conversion section can be changed. For example, in fig. 2J, the amount of the void 158 of the second wavelength converting region 36 is larger than that of the first wavelength converting region 35. Therefore, reflection of the excitation light can be enhanced at the side face 35 c.

Here, the first wavelength conversion unit 35 includes a first emission region 41 in which a part of the propagation light 82 enters and emits the wavelength-converted light, and the second wavelength conversion unit 36 includes a second emission region 42 in which a part or all of the propagation light not entering the first wavelength conversion unit 35 among the propagation light 82 enters and emits the wavelength-converted light.

At this time, as shown in fig. 2B, the first surface 35a of the first wavelength converting region 35 is, for example, a quadrangle, and the second wavelength converting region 36 surrounds the periphery thereof, as seen from the incident side of the propagating light 82 (in a plan view of the surface of the support member 32 on which the wavelength converting region 38 is disposed). Therefore, the first emission region 41 corresponds to the first surface 35a, and the second emission region 42 corresponds to the first surface 36a of the second wavelength conversion region 36. In the present embodiment, the first emission region 41 coincides with the first surface 35a, and the second emission region 42 coincides with the first surface 36 a.

At this time, the first wavelength conversion unit 35 and the second wavelength conversion unit 36 wavelength-convert at least a part of the incident propagation light 82 to generate fluorescence, and emit the fluorescence from the first surfaces 35a and 36a, respectively.

Specifically, as shown in fig. 2C, the incident light 82a, which is a part of the propagation light 82, is incident on the first emission region 41 of the first surface 35a of the first wavelength converting region 35. A part of the incident light 82a is wavelength-converted by the first wavelength converting region 35, and then emitted from the first emission region 41 as fluorescence (wavelength-converted light) 94 a. The incident light 82a having no wavelength conversion in the first wavelength conversion unit 35 is scattered and is emitted as scattered light 93a from the first emission region 41. Accordingly, the light emitted 91, which is a mixed light of the fluorescent light 94a and the scattered light 93a, is emitted from the first emission region 41.

Here, a part of the incident light 82a entering the first wavelength converting region 35 is the incident light 85a propagating inside the first wavelength converting region 35 and reflected multiple times on the second surface 35b and the side surface 35 c. In this case, since the side surface 35c is constituted by the interface between the first wavelength converting region 35 and the second wavelength converting region 36 having different average refractive indices as described above, the incident light 85a can be easily reflected. The fluorescence 86a generated by wavelength-converting the incident light 85a in the first wavelength converting region 35 can be similarly reflected multiple times. As described above, the excitation light and the fluorescence are reflected multiple times in the first wavelength converting region 35, and thus the emission intensity distribution of the light emitted 91 from the first emission region 41 can be made uniform as compared with the case where the first wavelength converting region 35 and the second wavelength converting region 36 are completely identical in structure.

On the other hand, the second wavelength conversion unit 36 also performs wavelength conversion.

Incident light 82b, which is a part of the propagation light 82 that does not enter the first surface 35a, enters the first surface 36a of the second wavelength converting region 36. The incident light 82b is partially wavelength-converted by the second wavelength converting region 36, and is emitted from the second emission region 42 as fluorescence 94 b. The incident light 82b having no wavelength conversion in the second wavelength conversion unit 36 is scattered, and is emitted as scattered light 93b from the second emission region 42. Accordingly, the light 92, which is a mixed light of the fluorescent light 94b and the scattered light 93b, is emitted from the second emission region 42.

Here, the ratio of the luminous flux of the fluorescent light emitted per unit light amount of the incident light is set as

(number 1)

The wavelength conversion efficiency of the second emission region 42 is designed to be lower than that of the first emission region 41. In the present embodiment, the second wavelength converting region 36 is designed to be lower than the first wavelength converting region 35 with respect to the intensity ratio of fluorescence to scattered light. Here, in expression 1, the conversion coefficient is a coefficient S for converting the fluorescent luminous flux from visual acuity according to a spectrum, and is calculated from expression 2 below using a spectral distribution Φeλ and a visual acuity curve kλ related to a wavelength λ [ nm ].

(number 2)

Hereinafter, a more specific structure of the wavelength conversion element 30 will be described.

The support member 32 of the wavelength conversion element 30 is a member in which a wavelength conversion portion 38 (i.e., a first wavelength conversion portion 35 and a second wavelength conversion portion 36) is disposed on a main surface. The support member 32 preferably has a high light reflectance with respect to the wavelength of 380nm to 780nm on the main surface where the wavelength conversion portion 38 is disposed. Further, the support member 32 is preferably formed of a material having high thermal conductivity. Accordingly, the support member 32 increases the proportion of the amount of light emitted from the first emission region 41 with respect to the amount of light generated in the first wavelength converting region 35, and also functions as a heat sink for radiating heat generated in the first wavelength converting region 35.

The support member 32 is formed of, for example, a crystalline material, a metal material, a ceramic material, or the like. More specifically, as the support member 32, a member in which an optical film that reflects light having a wavelength of 380nm780nm is formed on the surface of a crystal material such as silicon, sapphire, or diamond, or a ceramic material such as aluminum nitride, silicon carbide, or diamond can be used. In the present embodiment, the reflecting member 31 is formed on the main surface of the support member 32 where the wavelength converting region 38 is arranged, using a silicon substrate. For the reflecting member 31, a metal film of Ag, al, or the like can be used. The support member 32 may be made of a metal material such as silver, copper, aluminum, or an alloy thereof.

The first wavelength converting region 35 and the second wavelength converting region 36 each include a phosphor material and have a different average refractive index, as described with reference to fig. 2D, 2E, 2F, 2G, 2H, and 2I. In this configuration, the conversion efficiency of the second wavelength converting region 36 into fluorescence can be freely designed to be different from the conversion efficiency of the first wavelength converting region 35. Specific configurations and effects of the first wavelength converting region 35 and the second wavelength converting region 36 will be described with reference to fig. 2F and 2G.

The first wavelength converting region 35 includes, for example, ce active a ₃ B ₅ O ₁₂ A phosphor such as garnet crystal phosphor containing a YAG phosphor represented by (a includes Sc, Y, sm, gd, tb, lu, and B includes Al, ga, and In). More specifically, Y is activated in addition to Ce ₃ Al ₅ O ₁₂ In addition to the monocrystals of (2), Y may be activated by Ce, for example as shown in FIG. 2F ₃ Al ₅ O ₁₂ Is shown in FIG. 2G, and Ce activated Y ₃ A1 ₅ O ₁₂ Particles and Al ₂ O ₃ The particles are mixed andand a sintered ceramic YAG phosphor. The first wavelength conversion portion 35 is fixed to the central portion of the surface 31a of the reflecting member 31 by an adhesive such as a silicone resin, not shown.

On the other hand, the second wavelength converting region 36 is formed by mixing, for example, phosphor particles having an average particle diameter (central diameter) D50 of 0.5 μm to 5 μm, for example, with a transparent binder such as silicone resin, in a volume ratio of 50vol%, as in the first wavelength converting region 35, and includes a YAG-based phosphor. The second wavelength converting region 36 is disposed in close contact with the side surface 35c of the first wavelength converting region 35. Such a second wavelength converting region 36 can be easily formed by fixing the first wavelength converting region 35 to the support member 32, and then applying and curing the paste-like second wavelength converting region 36 around the first wavelength converting region 35.

At this time, the surface area of the phosphor particles per unit volume of the second wavelength converting region 36 can be increased compared to the case of using phosphor particles having an average particle diameter of 5 to 20 μm by using small phosphor particles having an average particle diameter D50 of 0.5 to 5 μm for the phosphor particles constituting the second wavelength converting region 36. With this configuration, the area of the interface 356 having the refractive index difference of the second wavelength converting region 36 can be increased. Therefore, the proportion of scattering and reflection of the incident light by the second wavelength converting region 36 can be increased as compared with the first wavelength converting region 35. Therefore, the excitation light incident from the outside in the second wavelength converting region 36 is reflected at a position closer to the surface than the first wavelength converting region 35, and is emitted to the outside. Therefore, the distance of the optical path of the excitation light propagating inside the second wavelength converting region 36 becomes shorter, and therefore the wavelength conversion efficiency of the second wavelength converting region 36 can be made smaller than that of the first wavelength converting region 35.

In the above configuration, the first wavelength converting region 35 is a single-or multi-crystalline phosphor having a refractive index similar to that of the YAG phosphor (wavelength 550nm, refractive index approximately 1.84), and a refractive index distribution in the first wavelength converting region 35 is small. The structural material of the second wavelength converting region 36 is a material in which phosphor particles 156 as a YAG phosphor are mixed with a transparent bonding material 256 as a silicone resin (refractive index is approximately 1.4), and the average refractive index of the first wavelength converting region 35 and the second wavelength converting region 36 is designed to be different. According to these structures, as shown in fig. 2C, the incident light 82a that enters the first wavelength converting region 35 propagates inside the first wavelength converting region 35, is reflected multiple times on the side surface 35C and the second surface 35b that is an adhesion surface with the reflecting member 31, and is wavelength-converted. The fluorescence 94a converted by the first wavelength converting region 35 also propagates inside the first wavelength converting region 35, is reflected multiple times by the second surface 35b, the side surface 35c, and the like, and is emitted from the first emission region 41. Therefore, even if the incident light (propagation light) 82a entering the first emission region 41 is light having a large site dependence of the light intensity distribution, the uniformly scattered light 93a and the fluorescence 94a having a small site dependence of the light intensity distribution can be emitted from the first emission region 41.

At this time, the second wavelength converting region 36 has a larger scattering reflection of the incident light and fluorescence in the vicinity of the interface than the first wavelength converting region 35. Therefore, the side face 35c can enhance the multiple reflection of the incident light and the fluorescence.

The effect is that, as shown in FIG. 2G, the first wavelength converting region 35 is formed by using a YAG phosphor as the phosphor particles 155 and Al as the transparent bonding material 255 ₂ O ₃ The ceramic phosphor having a refractive index of approximately 1.77 is also remarkable. This is because the refractive index difference between the phosphor particles and the transparent bonding material is smaller than that of a mixture of the YAG phosphor and silicone resin (refractive index of approximately 1.4) constituting the second wavelength conversion unit 36. According to this configuration, the incident light can be easily transmitted through the first wavelength conversion portion, and can be easily reflected by the side surface or the like a plurality of times.

Next, the optical effect of the wavelength conversion element 30 will be described in more detail with reference to fig. 3 and 4.

Fig. 3 is a schematic cross-sectional view for explaining the function of the wavelength conversion element 30 according to the present embodiment. Fig. 4 is a graph showing schematic luminance distributions of the emission regions of the wavelength conversion element 30 according to the present embodiment and the wavelength conversion element according to the comparative example. Fig. 4 (a) shows luminance distributions of the first emission region 41 and the second emission region 42 of the wavelength conversion element 30 according to the present embodiment. Fig. 4 (b) shows a luminance distribution of an emission region of the wavelength conversion element according to the comparative example.

As shown in fig. 3, the propagation light 82 is irradiated to the wavelength converting element 30 from directly above the first wavelength converting region 35 or in a substantially oblique direction. At this time, as the propagation light 82, for example, laser light having a center wavelength between 380nm and 490nm is irradiated from a spatially separated position. The laser light propagating from the spatially separated position generally has a strong intensity on the central axis 82i, and gradually decreases in intensity as it moves away from the central axis 82 i. That is, the intensity distribution of the laser light propagating from the spatially separated position shows a gaussian distribution shown as the light intensity distribution 83 of fig. 3. At this time, the excitation light having a strong light intensity near the center axis 82i among the propagation light 82 and the excitation light irradiated to the first wavelength conversion unit 35 is set as the incident light 82a. The excitation light that is relatively far from the center axis 82i and has a lower light intensity than the vicinity of the center axis 82i and that does not strike the first wavelength conversion unit 35 is set as the incident light 82b.

Here, the two-dimensional intensity distribution of the cross section perpendicular to the direction of the central axis 82i of the propagating light 82 is assumed to be an ideal gaussian distribution in a concentric circle. In the cross section including the central axis 82i of the propagating light 82, the light intensity of the propagating light 82 is maximized from the position at which the light intensity of the propagating light 82 is maximized to 1/e of the light intensity of the propagating light 82 at the maximum value ² The distance between the positions (approximately 13.5%) was ω ₀ . The diameter of the cross section of the propagating light 82 is 2ω ₀ . That is, the light intensity is 1/e of the center intensity (peak intensity) ² The width of the region (approximately 13.5%) or more is 2ω ₀ 。

At this time, as shown in fig. 3, when the incident angle of the propagation light 82 to the first surface 35a of the first wavelength converting region 35 is θ, the light intensity becomes 1/e of the center intensity on the first surface 35a ² The width of the above region becomes 2ω ₀ /cos θ。

At this time, if the width W3 of the first wavelength converting region 35 shown in fig. 3 is set to 2ω ₀ And/cos θ or more, the peak value of the light intensity of the incident light 82b entering the second wavelength converting region 36 is 13.5% or less, that is, between 0 and 13.5% of the peak value of the light intensity of the incident light 82a entering the first wavelength converting region 35.

The light emitted from the wavelength conversion element 30 when the propagation light 82 enters the wavelength conversion element 30 as described above will be described with reference to fig. 4.

Fig. 4 is a graph (a) schematically showing the luminance distribution of the light emitted from the first emission region 41 and the second emission region 42 when the incident light is incident on the wavelength conversion element 30 according to the present embodiment. Fig. 4 (b) shows, as a comparative example, the luminance distribution of the light emitted from the first emission region 41 and the second emission region 42 when the incident light is incident on the wavelength conversion elements of the first wavelength conversion portion and the second wavelength conversion portion made of the same material.

As shown in graph (b) of fig. 4, a luminance distribution reflecting the light intensity distribution of the incident light was obtained in the wavelength conversion element according to the comparative example. On the other hand, as shown in graph (a) of fig. 4, in the light source device 100 using the wavelength conversion element 30 according to the present embodiment, a substantially uniform luminance distribution is obtained in the first emission region 41 as the central portion of the emitted light, and the luminance is suppressed to be low in the second emission region 42 as the peripheral portion of the emitted light. That is, a uniform and high-luminance distribution is obtained only in the central portion of the emission region.

This is because the incident light 82a is reflected multiple times by the first wavelength converting region 35, which is the central portion of the emitted light, and the emitted light intensity becomes uniform in the first wavelength converting region 35 (first emission region 41). The fluorescence 86a generated in the first wavelength converting region 35 is also uniformly reflected by the first wavelength converting region 35 a plurality of times.

The luminous flux of the entire emitted light of the wavelength conversion unit 38 is approximately the same as that of the conventional wavelength conversion element.

The effect of the projected image of the light source device 100 having the above-described configuration will be described with reference to fig. 1, 5, and 6A to 6C.

Fig. 5 is a diagram schematically showing a projection image obtained by the illumination device 200 combining the light source device 100 and the light projecting member 120 according to the present embodiment. Fig. 6A and 6B are graphs showing spectra of the light emitted 91 and 92 from the first emission region 41 and the second emission region 42 of the light source device 100 according to the present embodiment, respectively. Fig. 6C is a chromaticity diagram showing the color distribution of projection light of the light source device 100 according to the present embodiment. Also, fig. 6C also shows the chromaticity coordinate area of white light specified by the ECE (Economic Commission for Europe) standard.

The light emitted 91 and 92 emitted from the wavelength conversion element 30 of the present embodiment are emitted as light emitted 95 from the light source device 100 as shown in fig. 1. The emitted light 95 is projected to a predetermined position as projection light 96 by a light projecting member 120 as a projection lens, for example. As shown in fig. 5, the projection light 96 projected at this time forms a projection image 99a composed of the projection light emitted from the first emission region 41 and a projection image 99b composed of the projection light emitted from the second emission region 42. However, the illuminance of the projection light forming the projection image 99b is low, and the illuminance of the projection light forming the projection image 99a is uniform and high. The illuminance changes sharply at the boundary between the projection image 99a and the projection image 99b. As described above, in the illumination device 200 according to the present embodiment, the projection light 96 having a large contrast between the projection image 99a and the projection image 99b around the projection image can be obtained.

Therefore, for example, when the illumination device 200 according to the present embodiment is used as a vehicle headlamp, it is possible to easily control the illuminance distribution such as increasing the illuminance of the road surface toward the far side and decreasing the illuminance of the sidewalk or the like toward the periphery thereof.

The chromaticity of the area where the illuminance is low, that is, the chromaticity of the projected image 99b, is obtained by mixing the spectrum of the excitation light 81 emitted from the semiconductor light emitting device 10 with the spectrum of the fluorescence 94b generated in the second wavelength conversion unit 36. Therefore, it is possible to suppress the projected image 99a and the projected image 99b from being configured to have a greatly different chromaticity. Specifically, for example, as shown in fig. 5, when a person traverses the optical path of the projection light 96, it is possible to suppress the perception of blue light corresponding to the excitation light, and the perception of white light corresponding to the mixture of scattered light and fluorescence.

Specifically, for example, as shown in fig. 6A and 6C, the scattered light 93a as chromaticity coordinates (0.16,0.01) and the fluorescent light 94a as chromaticity coordinates (0.44,0.54) are mixed, and the white light of chromaticity coordinates (0.34,0.35) is emitted from the first emission region 41 as the emitted light 91. The light 91 is emitted and projected to a predetermined position as a projected image 99a.

On the other hand, as shown in fig. 6B and 6C, the second emission region 42 emits the emission light 92 of white light of chromaticity coordinates (0.29,0.25) in which the scattered light 93B of chromaticity coordinates (0.16,0.01) and the fluorescent light 94B of chromaticity coordinates (0.44,0.54) are mixed. The emitted light 92 is projected to a predetermined position as a projected image 99b. At this time, the projected image 99b can project light closer to the chromaticity coordinates of the projected image 99a than the scattered light 93 b. Therefore, the chromaticity distribution of the blue irradiation light existing in the peripheral region of the projection image can be suppressed. The difference in chromaticity coordinates between the emitted light 91 and the emitted light 92 is due to the difference in the intensity ratio of scattered light to fluorescence as shown in fig. 6A and 6B.

As shown in fig. 6C, the chromaticity coordinates of the light emitted 91 occupying most of the light emitted 95 from the light source device 100 are included in the chromaticity coordinate region of white light in the ECE standard, and therefore the light source device 100 can be used as, for example, a headlight for a vehicle. That is, chromaticity coordinates of white light of the entire emitted light 95 can be set within the ECE standard, and can be used as a headlight for an automobile.

The structures of the first wavelength converting region 35 and the second wavelength converting region 36 are not limited to those described above. For example, as shown in fig. 2E, a mixture of phosphor particles having an average particle diameter D50 of 5 μm to 20 μm and a transparent binder may be used for the first wavelength conversion portion 35, and a mixture of phosphor particles having an average particle diameter D50 of 0.5 μm to 5 μm and a transparent binder may be used for the second wavelength conversion portion 36. Accordingly, the surface area of the phosphor particles per unit volume of the second wavelength converting region 36, that is, the refractive index interface 356 can be made larger than the surface area of the phosphor particles per unit volume of the first wavelength converting region 35, that is, the refractive index interface 355. As a result, the reflectance of the light from the first wavelength converting region 35 toward the second wavelength converting region 36 on the side surface 35c can be increased, and the multiple reflection can be enhanced. In this case, the same material, for example, silicone resin, can be used for the transparent bonding material of the first wavelength converting region 35 and the second wavelength converting region 36.

In the case of using a single-crystal phosphor as the first wavelength converting region 35, as shown in fig. 2F, an interface 355 may be provided as a plurality of grain boundaries in the first wavelength converting region 35 in order to increase scattering properties inside the first wavelength converting region 35. The pellet may further include an air hole 455a and an intra-pellet air hole 455b. Accordingly, the scattering property increases, and the excitation light is reflected multiple times in the first wavelength conversion portion 35, whereby the light emission distribution can be suppressed from becoming uneven.

As shown in fig. 2D, for example, the phosphor constituting the first wavelength converting region 35 may be phosphor particles 155 that are YAG-based phosphors, and the phosphor constituting the second wavelength converting region 36 may be phosphor particles 156 that are silicate-based phosphors, so that the phosphor materials of the first wavelength converting region 35 and the second wavelength converting region 36 may be different from each other. Accordingly, the scattering degrees in the first wavelength converting region 35 and the second wavelength converting region 36 can be made different. Accordingly, the wavelength conversion efficiency of the first wavelength converting region 35 and the second wavelength converting region 36 can be freely changed.

Further, according to the above-described method, by changing the structures of the first wavelength converting region 35 and the second wavelength converting region 36, the chromaticity coordinate x of the first wavelength converting region 35 can be set smaller than the chromaticity coordinate x of the second wavelength converting region 36, and the chromaticity coordinate of the white light of the entire emitted light 95 can be set within the ECE standard, so that the white light can be used as a headlight for an automobile. In this case, the chromaticity coordinates of the central portion of the projection image are easily set smaller than those of the peripheral portion.

The cross-sectional shape and cross-sectional area of the excitation light of the incident surface on which the excitation light (propagation light 82) of the first wavelength converting region 35 is incident may be substantially equal to the shape and area of the incident surface of the first wavelength converting region 35. Accordingly, the uniformity of the luminance distribution in the central portion of the light-emitting region can be improved, and the emission of excitation light from the periphery of the light-emitting region without mixing with fluorescence can be suppressed.

The first wavelength conversion unit 35 may include a first emission region 41 into which excitation light (propagation light 82) is incident, and the shape and cross-sectional area of the excitation light cross-section of the incident surface of the first emission region 41 into which the excitation light is incident may be substantially equal to the shape and area of the incident surface of the first emission region 41. Accordingly, the uniformity of the luminance distribution in the central portion of the light-emitting region can be improved, and the emission of excitation light from the periphery of the light-emitting region without mixing with fluorescence can be suppressed.

Specific structural example

Next, a more specific configuration of the light source device 100 according to the present embodiment will be described with reference to the drawings.

Fig. 7 is a schematic cross-sectional view showing a schematic configuration of the lighting device 200 using the light source device 100 according to the present embodiment. Fig. 8 is a schematic cross-sectional view showing a specific structure of the wavelength conversion element 30 of the light source device 100 according to the present embodiment.

In fig. 7, the semiconductor light emitting device 10, the condensing optical system 20, and the wavelength conversion element 30 are fixed to a case 50 made of, for example, an aluminum alloy. The case 50 is sealed by a cover member 61, which is a glass cover, for example. The optical axes of the excitation light 81 and the propagation light 82 are disposed in a space enclosed by the case 50 and the cover member 61. In the semiconductor light emitting device 10, the semiconductor light emitting element 11 is mounted on a package 13, which is, for example, a TO-CAN package. In the wavelength conversion element 30, the first wavelength converting region 35 is fixed to the reflecting member 31 of the support member 32, and the second wavelength converting region 36 is formed around the reflecting member. The light source device 100 thus configured is fixed to the heat sink 75 as a heat sink, for example. A light projecting member 120 as a projection lens is disposed on the optical paths of the light beams 91 and 92 emitted from the light source device 100.

As described above, the lighting device 200 including the light source device 100, the light projecting member 120, and the heat radiating member 75 can be configured.

Next, a more specific configuration of the wavelength conversion element 30 included in the light source device 100 shown in fig. 7 will be described with reference to fig. 8.

In the wavelength conversion element 30, the first wavelength conversion portion 35 and the second wavelength conversion portion 36 are formed of, for example, siO ₂ TiO ₂ A metal oxide film of Ag, al, or the like, or a metal film of Ag, al, or the like. The reflecting member 31 is supported by a supporting member 32 composed of, for example, a silicon substrate. Further, for example, the surface of the support member 32 made of a silicon substrate may be formed with irregularities 32c shown in fig. 8 by photolithography and etching, and the reflective member 31 may be formed on the surface of the support member 32 where the irregularities 32c are formed. Further, for example, ce-activated YAG and a phosphor Al ₂ O ₃ The first wavelength conversion region 35 of the mixed and sintered ceramic phosphor is fixed to the central portion of the surface 31a by a bonding material 34, which is a silicone adhesive material, for example. In this case, it is preferable that the first surface 35a, the second surface 35b, and the side surface 35c of the first wavelength converting region 35 have a concave-convex surface, so that multiple reflection and scattering of light are enhanced. Further, around the first wavelength converting region 35, a second wavelength converting region 36 composed of a mixture of phosphor particles 156, for example Ce-activated YAG phosphor particles having an average particle diameter D50 of 2 μm, and a transparent bonding material 256, for example silsesquioxane, is arranged.

With such a configuration, the wavelength conversion element 30 can be easily configured.

On the surface of the support member 32 where the wavelength conversion portion 38 is not disposed, an adhesive layer 39 is formed as a metal film of Ti, au, or the like, for example, and is fixed to the case 50 by a solder or the like, not shown.

(modification of example 1)

Next, modification 1 to modification 4 of embodiment 1 will be described with reference to the drawings.

Fig. 9A is a schematic cross-sectional view showing a schematic configuration of a wavelength conversion element 30A according to modification 1 of the present embodiment. Fig. 9B is a schematic cross-sectional view showing a schematic configuration of a wavelength conversion element 30B according to modification 2 of the present embodiment. Fig. 10A is a schematic cross-sectional view showing a schematic configuration of a wavelength conversion element 30C according to modification 3 of the present embodiment. Fig. 10B is a schematic cross-sectional view showing a schematic configuration of a wavelength conversion element 30D according to modification 4 of the present embodiment.

As in the wavelength conversion element 30A according to modification 1 shown in fig. 9A, the second wavelength conversion portion 36 may cover an edge portion of the first surface 35a (upper surface in fig. 9A) of the first wavelength conversion portion 35. In other words, the second wavelength converting region 36 may cover a portion other than the central portion of the first surface 35a of the first wavelength converting region 35. In the wavelength conversion element 30A according to the present modification, the first emission region 41 can be defined as a central region of the first surface 35a, which is not covered by the second wavelength conversion portion 36, that is, a region of the first surface 35a, which is exposed to the outside.

In the wavelength conversion element 30A having such a configuration, the incident light 85a reflected multiple times by the first wavelength converting region 35 is reflected not only by the side surface 35c and the second surface 35b but also by a part of the first surface 35a, and therefore, the wavelength conversion efficiency of the first wavelength converting region 35 can be improved. In this case, the thickness of the second wavelength converting region 36 on the first wavelength converting region 35 is set to be smaller than the thickness of the first wavelength converting region 35. Preferably, the number is half or less. According to this configuration, the light 91 emitted from the first wavelength converting region 35 can be emitted through the second wavelength converting region 36 on the first wavelength converting region 35, and therefore, as in embodiment 1, the uniformity of the luminance distribution in the central portion of the light emitting region of the wavelength converting element can be improved.

The wavelength conversion element 30A according to the present modification example includes a support member 32r formed of a material having a high reflectance with respect to light having a wavelength of 380nm to 780 nm. The support member 32r is formed of a metal material such as silver, copper, aluminum, or an alloy thereof, for example. Accordingly, there is no need to provide a reflective member separately on the support member. Further, the support member 32r is formed of a metal material having high thermal conductivity, so that the support member 32r having high heat radiation performance can be realized.

As in the wavelength conversion element 30B according to modification 2 shown in fig. 9B, a part of the side surface 35c of the first wavelength conversion region 35 on the first surface 35a side may not be covered with the second wavelength conversion region 36.

In the wavelength conversion element 30B having such a structure, the thickness of the second wavelength conversion region 36 can be reduced relative to the thickness of the first wavelength conversion region 35. Therefore, the wavelength conversion efficiency of the second wavelength converting region can be easily reduced relative to that of the first wavelength converting region. Therefore, the contrast of the luminance distribution of the central portion and the peripheral portion of the light emitting region of the wavelength conversion element can be improved.

In the wavelength conversion element 30C according to modification 3 shown in fig. 10A, the first wavelength conversion portion 35 is fixed to the support member 32, and the second wavelength conversion portion 36 is formed so as to surround the first wavelength conversion portion 35. At this time, between the first wavelength converting region 35 and the support member 32, for example, tiO having an average particle diameter of 0.1 to 10 μm dispersed in silicone resin may be provided ₂ A reflective member 31 of particles.

At this time, the reflecting member 31 may be formed only between the first wavelength converting region 35 and the supporting member 32. According to this structure, light reaching the second surface 35b of the first wavelength converting region 35, out of the light incident on the first wavelength converting region 35, is reflected by the reflecting member 31. Therefore, the first wavelength converting region 35 can efficiently convert the incident light 82a into the fluorescent light 94a, and the high-luminance light 91 can be emitted from the first wavelength converting region 35. On the other hand, the reflecting member 31 is not provided between the second wavelength converting region 36 and the supporting member 32.

Accordingly, the conversion efficiency of the incident light 82b into the fluorescent light 94b in the second wavelength converting region 36 is low, and thus the contrast can be improved.

As shown in the wavelength conversion element 30D according to modification 4 shown in fig. 10B, the side surface 35c of the first wavelength conversion portion 35 may be inclined. That is, the surface of the support member 32r on which the first wavelength converting region 35 is disposed may not be orthogonal to each other.

In the wavelength conversion element according to the present embodiment and the modified embodiment, the structures of the phosphor material and the transparent bonding material are not limited to those described above.

For the phosphor material, for example, an oxynitride-based phosphor (for example, β -SiAlON: eu ²⁺ ，Ca-d-SiAlON：Eu ²⁺ ，(Ca，Sr，Ba)SiO ₂ N ₂ ：Eu ²⁺ Etc.), nitride phosphors (e.g., caAlSiN ₃ ：Eu ²⁺ (La, Y, gd) ₃ Si ₆ N ₁₁ ：Ce ³⁺ Etc.), silicate-based fluorescent material (e.g., sr) ₃ MgSi ₂ O ₈ ：Eu ²⁺ ，(Ba，Sr，Mg) ₂ SiO ₄ ：Eu ²⁺ Etc.), phosphate-based phosphor (Sr) ₅ (PO ₄ ) ₃ Cl：Eu ²⁺ Etc.), or quantum dot phosphors (nanoparticles of InP, cdSe, etc.), etc.

At this time, the fluorescent material that emits the desired fluorescence is selected, so that the light source device 100 can emit the light having the desired chromaticity coordinates. For example, the emitted light of green, yellow, red, or the like can be emitted. Further, white light can be emitted from the light source device 100 by combining a plurality of phosphors to form the first wavelength converting region 35, or by combining chromaticity coordinates of the fluorescent light emitted from the first wavelength converting region 35 and chromaticity coordinates of the excitation light reflected by the first wavelength converting region 35. For example, in the case of using the semiconductor light-emitting element 11 that emits excitation light of near ultraviolet light having a peak wavelength of approximately 405nm, sr as a blue phosphor is used as the phosphor material ₅ (PO ₄ ) ₃ Cl：Eu ²⁺ And YAG as a yellow phosphor: ce (Ce) ³⁺ To obtain white light. In the case of using a semiconductor light-emitting element that emits excitation light having a peak wavelength of blue of approximately 445nm, YAG as a yellow phosphor is used as a phosphor material: ce (Ce) ³ + OR (La, Y) ₃ Si ₆ N ₁₁ ：Ce ³⁺ Thereby obtaining white light. For a pair ofIn the case of using a material containing siloxane coupling, for example, a bonding material containing a highly heat-resistant silicone resin and silsesquioxane can be used as the transparent bonding material for holding a phosphor material. In the case of using an inorganic material, siO can be used ₂ 、ZnO、ZrO ₂ 、Nb ₂ O ₅ 、Al ₂ O ₃ 、TiO ₂ SiN, alN, etc.

Example 2

Next, a light source device according to embodiment 2 will be described. The configuration of the light source device according to the present embodiment is the same as that of the light source device according to embodiment 1 and its modification shown in fig. 1 to 5 and fig. 7 to 10B, and therefore, the description thereof will be omitted.

In the light source device according to the present embodiment, the second wavelength converting region 36 includes a phosphor material different from that of the first wavelength converting region 35. Accordingly, the conversion efficiency of the second wavelength converting region into fluorescence and the spectrum of the emitted light can be freely designed to be different from those of the first wavelength converting region.

The light source device according to the present embodiment is characterized in that the x-coordinate of the chromaticity coordinates of the fluorescent light generated in the second wavelength converting unit 36 is larger than the x-coordinate of the chromaticity coordinates of the fluorescent light generated in the first wavelength converting unit 35. Hereinafter, a light source device according to the present embodiment will be described with reference to the drawings.

Fig. 11 is a chromaticity diagram showing chromaticity coordinates of light emitted from the light source device according to the present embodiment.

In the chromaticity diagram shown in fig. 11, chromaticity coordinates of the scattered light 93a and the fluorescent light 94a emitted from the first wavelength converting region 35, the scattered light 93b and the fluorescent light 94b emitted from the second wavelength converting region 36, and the projected images 99a and 99b as mixed light of the light source device according to the present embodiment are depicted. In the present embodiment, the x-coordinate of the chromaticity coordinates of the fluorescence 94b generated at the second wavelength converting region 36 is larger than the x-coordinate of the chromaticity coordinates of the fluorescence 94a generated at the first wavelength converting region 35. The chromaticity coordinates of the projection image 99a emitted from the first wavelength converting region 35 and the chromaticity coordinates of the projection image 99b emitted from the second wavelength converting region 36 are located substantially on the blackbody radiation locus.

In the present embodiment, the amount of the scattered light 93b of the second wavelength converting region 36 is very small compared to the amount of the scattered light 93a of the first wavelength converting region 35 due to absorption. Further, the light amount of the wavelength-converted light (fluorescence 94 b) of the second wavelength converting region 36 is lower than the light amount of the wavelength-converted light (fluorescence 94 a) of the first wavelength converting region 35. That is, the proportion of the scattered light 93b to the fluorescent light 94b in the light emitted from the second wavelength converting region 36 is lower than the proportion of the scattered light 93a to the fluorescent light 94a in the light emitted from the first wavelength converting region 35. At this time, the color temperature of the projection image 99b is lower than that of the projection image 99 a. Therefore, the visual acuity of the projected image 99b is lower than that of the projected image 99 a. Therefore, the contrast between the projected image 99a having high light intensity and the projected image 99b having low light intensity can be further improved.

Further, chromaticity coordinates of the projection image 99a and the projection image 99b are drawn on the blackbody radiation locus. Therefore, the light forming the projection image 99a and the projection image 99b does not become unnatural white light. For example, in the case where the proportion of scattered light of blue is large in the projection image 99b, the blue-white projection image 99b is projected around the white projection image 99a, and the user feels unnatural projection light. However, with the light source device according to the present embodiment, white light having low light intensity and visual acuity is projected around the white projection image 99a, and therefore, the user can be suppressed from feeling unnatural.

As shown in fig. 11, since the chromaticity coordinates of the projected image 99a and the projected image 99b are both included in white light defined by the ECE standard, the light source device according to the present embodiment can be used as, for example, a vehicle headlamp.

Fig. 12 is a diagram illustrating a function of a vehicle using the light source device according to the present embodiment.

As shown in fig. 12, the light source device according to the present embodiment is mounted on a vehicle 299, so that front light with high contrast can be projected forward.

Further, it is possible to suppress the occupant of the head car 199 from being exposed to unnatural light.

(modification of example 2)

Next, a light source device according to a modification of the present embodiment will be described. In the light source device according to the present modification, as in embodiment 2, different phosphor materials are used for the first wavelength converting region 35 and the second wavelength converting region 36.

In this modification, the propagation light 82 enters from the support member side of the wavelength conversion element. Therefore, the support member of the wavelength conversion element is made of a material transparent to the propagating light 82.

Fig. 13 is a schematic cross-sectional view showing the structure and function of the light source device 101 according to the present modification.

Fig. 14 is a diagram illustrating a specific configuration of the wavelength conversion element 130 for the light source device 101 according to the present modification.

As shown in fig. 13, the light source device 101 according to the present modification includes the semiconductor light emitting device 10, the condensing optical system 20, and the wavelength conversion element 130.

The semiconductor light-emitting device 10 is the same as the semiconductor light-emitting device 10 according to embodiment 1. The semiconductor light emitting device 10 is a device in which a semiconductor light emitting element 11, which is a nitride semiconductor laser, is mounted on a support member 12 and fixed to a package, not shown, for example. The excitation light 81 emitted from the optical waveguide 11a formed in the semiconductor light emitting element 11 is emitted to the condensing optical system 20. The condensing optical system 20 condenses the excitation light 81 having an emission angle in the horizontal direction and the vertical direction emitted from the semiconductor light emitting element 11, and generates the propagation light 82 as the excitation light that propagates spatially while being collimated or condensed to the wavelength conversion element 130. The propagation light 82 propagates along the central axis 82i and irradiates the wavelength conversion element 130.

The condensing optical system 20 is, for example, a lens.

The element 130 is an element that is disposed separately from the semiconductor light-emitting device 10, performs wavelength conversion on excitation light emitted from the semiconductor light-emitting device 10 to generate fluorescence, and transmits the excitation light to generate transmission light.

The wavelength conversion element 130 includes the support member 32 and the wavelength conversion unit 38 disposed on the support member 32, and the wavelength conversion unit 38 includes the first wavelength conversion unit 35 and the second wavelength conversion unit 36 disposed around the first wavelength conversion unit 35 so as to surround the first wavelength conversion unit 35 when viewed in plan on the surface of the support member 32 on which the wavelength conversion unit 38 is disposed. Here, the second wavelength converting region 36 is lower than the first wavelength converting region 35 with respect to the intensity ratio of fluorescence to transmitted light.

In the wavelength conversion element 130 according to the present modification, for example, the reflecting member 31, which is an optical film for reflecting fluorescence, is formed on one main surface of the supporting member 32, which is a substrate transparent to the propagating light 82. Further, the first wavelength converting region 35 and the second wavelength converting region 36 are fixed to the surface 31a of the reflecting member 31.

Hereinafter, the structure of the wavelength conversion element 130 will be described in more detail with reference to fig. 14.

For the support member 32, for example, a sapphire substrate with both surfaces optically polished at a thickness of 0.33mm is used. Further, on one main surface (upper surface in fig. 14) of the support member 32, for example, a reflection member 31 as a color separation film is formed. The reflecting member 31 is formed of a dielectric multilayer film, and transmits light having a wavelength shorter than 490nm in a direction perpendicular to the surface, and reflects light having a wavelength of 490nm or more. Furthermore, the larger the angle of incidence with respect to the surface is designed to reflect light shorter than the wavelength 490 nm. Then, on the other main surface (lower surface in fig. 14) of the support member 32, an antireflection film 33 made of one or more layers of dielectric films is formed.

The first wavelength converting region 35 and the second wavelength converting region 36 are fixed to the surface 31a of the support member 32 on the reflecting member 31 side.

The first wavelength converting region 35 is, for example, phosphor particles 155 made of Ce-activated YAG phosphor. The average particle diameter D50 of the phosphor particles 155 is between 1 μm and 20 μm. The phosphor particles 155 are fixed to the reflecting member 31 by a transparent bonding material 255 which is, for example, silsesquioxane. The first wavelength converting region 35 has a diameter of 600 μm and a thickness of 70 μm on the surface of the reflecting member 31.

The first wavelength conversion portion 35 is formed on the reflecting member 31 by an aperture mask, not shown. The aperture mask was 70 μm thick, and an aperture having a diameter of 600 μm was formed in the center. By using such an aperture mask, the paste-like member in which the phosphor particles 155 are mixed in the solution-like transparent bonding material 255 is transferred onto the reflecting member 31 and cured, whereby the first wavelength converting region 35 can be easily formed.

The second wavelength converting region 36 is formed by applying a mixture of phosphor particles different from the first wavelength converting region 35 and a transparent bonding material to the periphery of the first wavelength converting region 35 and curing the mixture.

The propagation light 82 is incident from the side of the reflection preventing film 33 of the wavelength conversion element 130 having the above-described structure. The incident light entering the first wavelength converting region 35 out of the propagating light 82 becomes incident light 85a scattered at the interface between the phosphor particles 155 and the transparent bonding material 255, and is reflected multiple times on the side surface 35 that is the interface between the first wavelength converting region 35 and the second wavelength converting region 36, and on the second surface 35b that is the interface between the first wavelength converting region 35 and the reflecting member 31. Some of the incident light 85a reflected multiple times is converted into fluorescence 86a by the wavelength of the phosphor particles 155. The fluorescence 86a is reflected inside the first wavelength converting region 35 a plurality of times, similarly to the incident light 85 a.

As a result, the incident light 85a and the fluorescent light 86a are uniformly distributed in the first wavelength converting region 35, and the scattered light 93a and the fluorescent light 94a, which are transmitted light, are emitted from the first surface 35a of the first wavelength converting region 35.

On the other hand, a part of the propagation light 82 incident on the second wavelength converting region 36 is wavelength-converted in the second wavelength converting region 36, and is emitted as fluorescence 94b from the first surface 36a of the second wavelength converting region 36. The other part of the propagation light 82 incident on the second wavelength converting region 36 is reflected multiple times in the second wavelength converting region 36 and is emitted as scattered light 93b, which is transmitted light.

In this way, the light emitted 91 as a mixture of the scattered light 93a (transmitted light) and the fluorescent light 94a and the light emitted 92 as a mixture of the scattered light 93b (transmitted light) and the fluorescent light 94b are emitted from the wavelength conversion element 130. The light 95 composed of the light 91 and the light 92 is emitted from the light source device 101, and is emitted as the projection light 96 as the substantially parallel light by the light projecting member 120 as the projection lens provided outside the light source device 101.

At this time, chromaticity coordinates of the scattered light 93a and the fluorescent light 94a emitted from the first wavelength converting region 35, the scattered light 93b and the fluorescent light 94b emitted from the second wavelength converting region 36, and the projected images 99a and 99b are designed to be coordinates of a chromaticity diagram depicted in fig. 11, for example. In the present modification, each chromaticity coordinate of the projection image 99a emitted from the first wavelength converting region 35 and the projection image 99b emitted from the second wavelength converting region 36 is located substantially on the blackbody radiation locus.

Further, the color temperature of the projection image 99b is lower than that of the projection image 99 a. Therefore, the visual acuity of the projected image 99b is lower than that of the projected image 99 a. Therefore, the contrast between the projected image 99a having high light intensity and the projected image 99b having low light intensity can be improved.

Further, since the chromaticity coordinates of the projection image 99a and the projection image 99b are located on the blackbody radiation locus, the projection image 99a and the projection image 99b do not become unnatural white light.

The first wavelength conversion unit 35 of the light source device 102 according to the present modification may include a first emission region 41 into which the propagation light 82 (excitation light) enters and from which the transmission light is emitted, and the cross-sectional shape and cross-sectional area of the propagation light 82 of the incidence plane into which the propagation light 82 of the first emission region 41 enters may be substantially equal to the shape and area of the incidence plane of the first emission region 41. Accordingly, the uniformity of the luminance distribution in the central portion of the light-emitting region can be improved, and the emission of excitation light from the periphery of the light-emitting region without mixing with fluorescence can be suppressed.

As in the above-described embodiments, the light source device of the present embodiment can be used as a vehicle headlamp, for example.

Example 3

Next, a light source device according to the present embodiment will be described. The wavelength conversion element for a light source device according to the present embodiment is different from the light source device 100 according to embodiment 1 in that not only the side surface 35c of the first wavelength conversion portion 35 is covered with the second wavelength conversion portion 36, but also the second surface 35b on the support member 32 side is covered with the second wavelength conversion portion 36. Hereinafter, the light source device according to the present embodiment will be described with reference to the drawings, focusing on differences from the light source device according to embodiment 1 with respect to the wavelength conversion element 30.

Fig. 15 is a schematic cross-sectional view showing a schematic configuration of the wavelength conversion element 230 according to the present embodiment.

The wavelength conversion element 230 includes a support member 32, a reflecting member 31, and a wavelength conversion unit 38. The support member 32 is, for example, a silicon substrate. The reflecting member 31 is a reflecting film made of a metal film such as titanium, platinum, aluminum, or silver, for example, and is formed on the surface of the supporting member 32 where the wavelength converting region 38 is disposed. Further, for the support member 32, an aluminum plate or an aluminum alloy plate may be used. In this case, the support member 32 has a function as a reflecting member, and thus, the reflecting member 31 does not need to be provided separately.

The wavelength conversion unit 38 includes a first wavelength conversion unit 35 and a second wavelength conversion unit 36. The first wavelength conversion portion 35 is, for example, a ceramic member containing a YAG-based phosphor, and is disposed on the reflecting member 31. As shown in fig. 15, the second surface 35b on the support member 32 side and the side surface 35c other than the first surface 35a (the upper surface in fig. 15) on which the incident light 82a is incident, among the surfaces of the first wavelength converting region 35, is covered with the second wavelength converting region 36. For the second wavelength converting region 36, for example, a mixed material of phosphor particles as YAG phosphor particles and a transparent bonding material 256 as silsesquioxane can be used.

With the above configuration, the average refractive index of the first wavelength converting region 35 and the average refractive index of the second wavelength converting region 36 can be made different. Therefore, a part of the incident light 82a entering the first wavelength converting region 35 can be reflected a plurality of times on the side surface 35c that is the interface between the first wavelength converting region 35 and the second wavelength converting region 36 disposed in the outer peripheral region thereof, and on the second surface 35b that is the interface between the first wavelength converting region 35 and the second wavelength converting region 36 disposed between the first wavelength converting region 35 and the support member 32. Accordingly, the emitted light 91 having a uniform light distribution can be efficiently emitted from the first wavelength conversion portion 35.

Fig. 16 is a sectional view showing a more specific structure of the wavelength conversion element 230 for the light source device of the present embodiment.

In fig. 16, the support member 32 is a silicon substrate. On the surface of the support member 32 where the first wavelength converting region 35 is disposed, irregularities are formed by wet etching, dry etching, or the like. The reflective member 31 is formed as a reflective film made of a metal film such as titanium, platinum, aluminum, or silver on the surface on which the irregularities are formed. Further, on the reflecting member 31, for example, a first wavelength conversion portion 35 as a ceramic member including a YAG-based phosphor is disposed. The first wavelength converting region 35 is Ce-activated Y ₃ Al ₅ O ₁₂ Particles and Al ₂ O ₃ The ceramic YAG phosphor in which the particles are mixed and fired is, for example, square with a side length of 400 μm to 500 μm and a thickness of 50 μm to 100 μm. Further, irregularities are formed on the surface of the first wavelength converting region 35 by, for example, physical processing such as grinding, or chemical processing such as wet etching or dry etching.

As shown in fig. 16, the first wavelength converting region 35 includes all of the side surfaces 35c and the second surface 35b covered with the second wavelength converting region 36, except for the first surface 35a on which the incident light 82a is incident. At this time, for the second wavelength converting region 36, a member fixed by a transparent bonding material 256, for example, silsesquioxane, using phosphor particles 156, for example, YAG phosphor particles having particle diameters distributed in a range of 1 μm to 4 μm. Here, the particle diameter distribution of 1 μm to 4 μm means that the average particle diameter D50 is 2 μm, D10 is 1 μm, and D90 is 4 μm. At this time, ce constituting the first wavelength converting region 35 activates Y ₃ Al ₅ O ₁₂ Particles and Al ₂ O ₃ The refractive index of the particles was approximately 1.84 and 1.77, respectively.

On the other hand, ce activation Y constituting the second wavelength converting region 36 ₃ Al ₅ O ₁₂ The refractive indices of the particles and silsesquioxane were approximately 1.84 and 1.5, respectively. Therefore, the refractive index difference between the phosphor particles of the second wavelength converting region 36 and the transparent bonding material is larger than that of the first wavelength converting region 35, and therefore, the phosphor particles are reflected at a position having a small distance from the surface.

Therefore, a part of the incident light 82a entering the first wavelength converting region 35 can be reflected multiple times on the side surface 35c that is the interface between the first wavelength converting region 35 and the second wavelength converting region 36 disposed in the outer peripheral region thereof, and the second surface 35b that is the interface between the first wavelength converting region 35 and the second wavelength converting region 36 disposed between the first wavelength converting region 35 and the support member 32, and therefore, the outgoing light 91 having a uniform light distribution can be efficiently emitted from the first wavelength converting region 35.

Further, a part of the incident light 82b of the propagation light 82, which enters the second emission region 42, is wavelength-converted by the phosphor particles 156 of the second wavelength converting region 36, and is emitted from the wavelength converting element 30 as fluorescence 94 b.

At this time, the conversion efficiency of the second emission region 42 is smaller than that of the first emission region 41, and therefore, the contrast of the emitted light can be increased at the boundary between the first emission region 41 and the second emission region 42.

On the other hand, since a part of the incident light 82b incident on the second emission region 42 becomes fluorescence 94b, the fluorescence is mixed with the scattered light 93b emitted from the second emission region 42, and is emitted from the wavelength conversion element. Therefore, the chromaticity coordinates of the light 92 emitted from the second emission region 42 are closer to those of the light 91 emitted from the first emission region 41 than the case where only the light scattered by the incident light 82b is emitted from the second emission region 42.

Therefore, the color distribution of the light emitted from the light source device can be made smaller.

[ method of production ]

Next, an example of a method for manufacturing the wavelength conversion element 230 according to the present embodiment will be described with reference to the drawings.

Fig. 17 is a schematic cross-sectional view showing each step of the method for manufacturing the wavelength conversion element 230 according to the present embodiment.

First, as shown in a cross-sectional view (a) of fig. 17, for example, a reflective member 31 made of a metal film formed on a support member 32 made of a silicon substrate is coated with, for example, a pasty second wavelength converting region 36 in which phosphor particles having an average particle diameter D50 of 1 μm to 4 μm are mixed with a transparent bonding material. In this case, a paste-like transparent bonding material in which silsesquioxane is dissolved in an organic solvent is used as the transparent bonding material. Further, the first wavelength converting region 35 is held by the vacuum chuck 150.

Next, as shown in a cross-sectional view (b) of fig. 17, the first wavelength converting region 35 is arranged on the pasty second wavelength converting region 36. At this time, the second wavelength converting region 36, which is pasty due to intermolecular forces between the first wavelength converting region 35 and the transparent bonding material, rises on the side surface of the first wavelength converting region 35. Therefore, the paste-like second wavelength converting region 36 can be easily covered, and at least a part of the lower surface and the side surface of the first wavelength converting region 35 can be easily covered.

Then, heating is performed to cure the second wavelength converting region 36.

At this time, for example, the organic solvent of the pasty second wavelength converting region 36 is volatilized and cured by heating at approximately 150 ℃ for approximately two hours.

In this way, the wavelength conversion element of the light source device of the present embodiment can be easily manufactured.

At this time, the pasty second wavelength converting region 36 is contracted, and therefore irregularities along the phosphor particles can be easily formed on the surface of the second wavelength converting region 36. Accordingly, the propagation light 82 can be scattered on the surface of the second wavelength converting region 36.

According to the above manufacturing method, the wavelength conversion element 230 of the light source device according to the present embodiment can be easily manufactured.

(modification of example 3)

Next, the mode of the light source device according to modification examples 1 to 3 of the present embodiment will be described with reference to the drawings.

Fig. 18A is a schematic cross-sectional view showing the structure of a wavelength conversion element 230A according to modification 1 of the present embodiment. Fig. 18B is a schematic cross-sectional view showing the structure of a wavelength conversion element 230B according to modification 2 of the present embodiment. Fig. 18C is a schematic cross-sectional view showing the structure of a wavelength conversion element 230C according to modification 3 of the present embodiment.

As in the wavelength conversion element 230A according to modification 1 shown in fig. 18A, the second wavelength conversion unit 36 may cover an edge portion of the first surface 35a (upper surface in fig. 18A) of the first wavelength conversion unit 35. In other words, the second wavelength converting region 36 may cover a portion other than the central portion of the first surface 35a of the first wavelength converting region 35. The wavelength conversion element 230A having such a structure can be easily configured by increasing the coating amount of the second wavelength conversion portion 36 shown in the cross-sectional view (a) in the manufacturing method shown in fig. 17. In the wavelength conversion element 230A having such a configuration, the incident light 85a reflected multiple times by the first wavelength converting region 35 is reflected not only by the side surface 35c and the second surface 35b but also by a part of the first surface 35a, and therefore, the wavelength conversion efficiency of the first wavelength converting region 35 can be improved. In this case, the thickness of the second wavelength converting region 36 on the first wavelength converting region 35 is set to be smaller than the thickness of the first wavelength converting region 35. Preferably, the number is half or less. According to such a configuration, the light 91 emitted from the first wavelength converting region 35 can be emitted through the second wavelength converting region 36 on the first wavelength converting region 35, and therefore, the uniformity of the luminance distribution in the central portion of the light emitting region of the wavelength converting element 230A can be improved.

As in the wavelength conversion element 230B according to modification 2 shown in fig. 18B, a part of the side surface 35c of the first wavelength conversion region 35 on the first surface 35a side may not be covered with the second wavelength conversion region 36. The wavelength conversion element 230A having such a structure can be easily formed by reducing the coating amount of the second wavelength conversion portion 36 shown in the cross-sectional view (a) in the manufacturing method shown in fig. 17.

In the wavelength conversion element 230B having such a structure, the thickness of the second wavelength conversion region 36 can be made thinner than the thickness of the first wavelength conversion region 35. Therefore, the wavelength conversion efficiency of the second wavelength converting region can be easily reduced relative to that of the first wavelength converting region. Therefore, in the light emission distribution of the light emission region of the wavelength conversion element, the contrast between the first emission region and the second emission region can be improved.

In the wavelength converting element 230C shown in fig. 18C, the second wavelength converting region 36 covers only the second face 35b of the first wavelength converting region 35. The wavelength conversion element 230A having such a structure can be easily configured by reducing the coating amount of the second wavelength conversion portion 36 shown in the cross-sectional view (a) in the manufacturing method shown in fig. 17.

In the wavelength conversion element 30 having such a configuration, the thickness of the second wavelength conversion region 36 can be made thinner than the thickness of the first wavelength conversion region 35. Therefore, the wavelength conversion efficiency of the second wavelength converting region can be easily reduced relative to that of the first wavelength converting region.

Example 4

Next, a light source device according to example 4 will be described. The light source device according to the present embodiment is different from the light source device according to each of the above embodiments in that the light source device mainly includes a photodetector. Hereinafter, a light source device according to the present embodiment will be described with reference to the drawings.

Fig. 19 is a schematic cross-sectional view showing a schematic configuration of the light source device 102 according to the present embodiment.

The light source device 102 shown in fig. 19 includes the semiconductor light emitting device 10, the wavelength conversion element 30, the first filter 23, the first photodetector 25, the second photodetector 26, and the third photodetector 27. In the present embodiment, the light source device 102 further includes a condensing optical system 20, a separating optical element 21, and a second filter 24.

The semiconductor light emitting device 10 emits laser light. In the present embodiment, the semiconductor light emitting device 10 emits coherent excitation light 81, and includes a semiconductor light emitting element 11. The semiconductor light emitting device 10 is fixed such that the light emitted from the semiconductor light emitting element 11 is emitted to the wavelength conversion element 30.

The semiconductor light emitting element 11 is a semiconductor laser element made of, for example, a nitride semiconductor, and emits laser light having a peak wavelength between 380nm and 490nm as excitation light 81. In the present embodiment, the semiconductor light emitting element 11 is mounted on a package 13, which is, for example, a TO-CAN package.

In the semiconductor light emitting element 11, an optical waveguide 11a is formed.

Power from outside of the light source device 102 is input to the semiconductor light emitting element 11. The laser light having a peak wavelength of 445nm, for example, generated in the optical waveguide 11a of the semiconductor light emitting element 11 is emitted as excitation light 81 to the condensing optical system 20.

The condensing optical system 20 condenses the excitation light 81, which is the laser light emitted from the semiconductor light emitting element 11, and irradiates the wavelength conversion element 30 with the condensed excitation light. The configuration of the condensing optical system 20 is not particularly limited as long as it can condense the excitation light 81. For the condensing optical system 20, for example, an aspherical convex lens can be used. The condensing optical system 20 condenses the excitation light 81 having an emission angle in the horizontal direction and the vertical direction emitted from the semiconductor light emitting element 11, and generates propagation light 82 that is excitation light that propagates spatially while being collimated or condensed to the wavelength conversion element 30. The propagation light 82 is irradiated to the wavelength conversion element 30.

The wavelength conversion element 30 irradiates fluorescence with laser light emitted from the semiconductor light emitting device 10 as excitation light. In the present embodiment, the wavelength conversion element 30 is configured to perform wavelength conversion on excitation light emitted from the semiconductor light emitting device 10 to generate fluorescence separately from the semiconductor light emitting device 10, and scatter the excitation light to generate scattered light. In the present embodiment, the wavelength conversion element 30 is irradiated with the propagation light 82 as excitation light, and at least a part of the propagation light 82 is wavelength-converted, thereby emitting wavelength-converted light.

The wavelength conversion element 30 includes a support member 32, and a wavelength conversion portion 38 disposed on the support member 32. The wavelength conversion unit 38 includes a first wavelength conversion unit 35, and a second wavelength conversion unit disposed around the first wavelength conversion unit 35 and surrounding the first wavelength conversion unit when the surface of the support member 32 on which the wavelength conversion unit 38 is disposed is viewed in plan. In the present embodiment, the wavelength conversion element 30 includes a reflecting member 31 formed between the support member 32 and the first wavelength conversion portion 35. In the light source device 102 according to the present embodiment, the structure of the wavelength conversion element 30 that can be used is not limited to the above-described structure. Any wavelength conversion element can be used in the light source device 102. For example, the wavelength conversion unit 38 may be provided with a single wavelength conversion member.

The separation optical element 21 is an element disposed on the optical path of the propagation light 82, and is configured to separate and guide a part of the propagation light 82 to the other optical path 82 d. For the separation optical element 21, for example, a beam splitter can be used.

The first filter 23 is an element into which a part of the light emitted from the wavelength conversion element 30 is incident. In the present embodiment, the first filter 23 selectively transmits the excitation light 81 to suppress the transmission of the fluorescent light emitted from the wavelength conversion element 30. The first filter 23 suppresses transmission of the scattered light 93 emitted from the wavelength conversion element 30, and substantially blocks the fluorescence 94. For the first filter 23, for example, a dielectric multilayer film filter can be used.

The second filter 24 is an element into which a part of the light radiated from the wavelength conversion element is incident. In the present embodiment, the second filter 24 is an optical element that selectively transmits the fluorescence 94 emitted from the wavelength conversion element 30 and suppresses the transmission of the excitation light 81. The second filter 24 transmits the fluorescence 94 and substantially blocks the scattered light 93 emitted from the wavelength conversion element 30. For the second filter 24, for example, a dielectric multilayer film filter can be used. The light source device 102 does not necessarily need to include the second filter 24.

The first photodetector 25 is a detector on which light passing through the first filter 23 is incident. In the present embodiment, the first photodetector 25 detects the intensity of the scattered light 93 incident via the first filter 23. For example, a photodiode or the like can be used for first photodetector 25.

The second photodetector 26 is a detector on which light passing through the second filter 24 is incident. In the present embodiment, the second photodetector 26 detects the intensity of the fluorescence 94 incident via the second filter 24. For the second photodetector 26, a photodiode or the like can be used, for example.

The third photodetector 27 is a detector into which excitation light 81 is incident. In the present embodiment, the intensity of the propagating light 82 separated by the separation optical element 21 is detected. For the third photodetector 27, a photodiode or the like can be used, for example.

An outline of the operation of the light source device 102 having the above-described configuration will be described.

The light emitted from the semiconductor light emitting device 10 is transmitted light 82 condensed by the condensing optical system 20, and is directed to the wavelength conversion element 30. The propagating light 82 passes through the separating optical element 21 before reaching the wavelength converting element 30. At this time, a part of the propagation light 82 is reflected and enters the third photodetector 27.

Most of the propagation light 82 incident on the wavelength conversion element 30 is incident on the first wavelength conversion portion 35 of the wavelength conversion element 30, and the other part of the propagation light 82 is incident on the second wavelength conversion portion 36.

In the first wavelength converting region 35, a part of the light is converted into fluorescence 94, and the other part of the light is scattered by the first wavelength converting region 35 to be scattered light 93, which is emitted from the wavelength converting element 30. The scattered light 93 and the fluorescent light 94 become emitted light 95, and are emitted from the light source device 102.

On the other hand, a part of the light 95 emitted as the mixed light emitted from the wavelength conversion element 30 is guided to the first photodetector 25 and the second photodetector 26. At this time, the light 95 emitted toward the first photodetector 25 enters the first filter 23. The light 95 emitted toward the second photodetector 26 enters the second filter 24.

Here, the function of the light source device 102 according to the present embodiment will be described with reference to the drawings.

Fig. 20 is a block diagram showing the paths of the propagation light 82 from the semiconductor light emitting device 10, the emitted light 95 from the wavelength conversion element 30, and the paths of the signals from the respective photodetectors in the light source device 102 according to the present embodiment.

A part of the propagation light 82 is separated by the separation optical element 21, enters the third photodetector 27, and is photoelectrically converted by the third photodetector 27 to become a photocurrent. The photocurrent is converted into a signal 125, which is a predetermined voltage signal, by a current-voltage converter provided inside or outside the third photodetector 27, and is input to the microcontroller 65. In fig. 19, the microcontroller 65 is not shown.

A part of the light 95 emitted from the wavelength conversion element 30 enters the first filter 23, and another part enters the second filter 24.

The first filter 23 is, for example, an optical filter that transmits light having a wavelength of less than 490nm and reflects light having a wavelength of 490nm or more. That is, the first filter 23 is an optical filter that transmits most of the light of the wavelength of the excitation light 81 emitted from the semiconductor light-emitting device 10 and reflects most of the light of the spectrum of the fluorescence 94 generated by the wavelength conversion element 30.

The second filter 24 is, for example, an optical filter that reflects light having a wavelength of less than 490nm and transmits light having a wavelength of 490nm or more. That is, the second filter 24 is an optical filter that reflects a large part of light of the wavelength of the excitation light 81 emitted from the semiconductor light-emitting device 10 and transmits a large part of light of the spectrum of the fluorescence 94 generated in the wavelength conversion element 30.

The light 95 incident on the first filter 23 is transmitted through the first filter 23 substantially only the component of the scattered light 93, and is received by the first photodetector 25.

The scattered light 93 received by the first photodetector 25 is photoelectrically converted into a photocurrent by the first photodetector 25. The photocurrent is converted into a signal 126, which is a predetermined voltage signal, by a current-voltage converter provided inside or outside the first photodetector 25, and is input to the microcontroller 65.

The emitted light 95 entering the second filter 24 is transmitted through substantially only the component of the fluorescence 94 in the second filter 24 and is received by the second photodetector 26.

The fluorescence 94 received by the second photodetector 26 is photoelectrically converted into a photocurrent by the second photodetector 26. The photocurrent is converted into a signal 127, which is a predetermined voltage signal, by a current-voltage converter provided inside or outside the second photodetector 26, and is input to the microcontroller 65.

In the light source device 102 according to the present embodiment, the status of the light source device 102 is diagnosed using the signals 125, 126, and 127 input to the microcontroller 65 as described above. The flow of signal processing by the microcontroller 65 of the light source device 102 will be described below with reference to the drawings.

Fig. 21 is a flowchart showing a flow of signal processing of the light source device 102 according to the present embodiment.

As shown in fig. 21, in the light source device 102 according to the present embodiment, the state of the light source device 102 is determined by the following signal processing.

First, the microcontroller 65 detects the light intensity PA of the scattered light 93 by the first photodetector 25 (step (a)).

Next, the microcontroller 65 detects the light intensity PB of the fluorescence 94 by the second photodetector 26 (step (B)).

Next, the microcontroller 65 detects the light intensity PC of the propagation light 82 by the third photodetector 27 (step (C)).

Next, the microcontroller 65 determines whether or not the light intensity PA of the scattered light 93 is within a predetermined range (step (D)). Here, when the light intensity PA of the scattered light 93 falls within the predetermined range (yes in step (D)), the process proceeds to step (F). On the other hand, when the light intensity PA of the scattered light 93 is not within the predetermined range (no in step (D)), it is determined that the light flux of the propagating light 82 has not reached the wavelength conversion element 30, and an error signal indicating that the light flux has not reached is output (step (I)).

The microcontroller 65 determines whether or not the light intensity PB of the fluorescent light 94 is within a predetermined range (step (E)). Here, when the light intensity PB of the fluorescence 94 is within the predetermined range (yes in step (E)), the process proceeds to step (F). On the other hand, when the light intensity PB of the fluorescent light 94 is not within the predetermined range (no in step (E)), it is determined that the light flux of the propagating light 82 does not reach the wavelength conversion element 30, and an error signal indicating that the light flux has not reached is output (step (J)).

When it is determined in step (D) that the light intensity PA of the scattered light 93 is within the predetermined range, and when it is determined in step (E) that the light intensity PB of the fluorescent light 94 is within the predetermined range, the microcontroller 65 calculates the intensity ratio PB/PA, and determines whether or not the intensity ratio PB/PA is within the predetermined range (step (F)). Here, when the intensity ratio PB/PA is within the predetermined range (yes in step (F)), the process proceeds to step (H). On the other hand, when the intensity ratio PB/PA is not within the predetermined range (no in step (F)), it is determined that the color of the emitted light is poor, and an error signal indicating "color failure" is output (step (K)).

When it is determined in step (G) that the light intensity PC of the propagating light 82 is within the predetermined range, and when it is determined in step (F) that the intensity ratio PB/PA is within the predetermined range, the microcontroller 65 calculates the intensity ratio PB/PC and determines whether the intensity ratio PB/PC is within the predetermined range (step (H)). Here, when the intensity ratio PB/PC is within the predetermined range (yes in step (H)), a normal signal indicating that the state of the light source device 102 is normal is output (step (N)). On the other hand, when the intensity ratio PB/PC is not within the predetermined range (no in step (H)), it is determined that the wavelength conversion efficiency of the wavelength conversion element 30 is reduced, and an error signal indicating "the wavelength conversion rate is reduced" is outputted (step (M)). In the above, the intensity ratio PA/PC may be used instead of the intensity ratio PB/PC.

As described above, the microcontroller 65 diagnoses the status of the light source device 102. In the structure, an error signal and a normal signal are output to the outside. An error signal output to the outside is transmitted to an external circuit, not shown, and a safety measure such as stopping the application of power to the light source device 102 is adopted.

With the above configuration, the light source device 102 can detect the ratio of the amount of scattered light 93 of the light emitted from the wavelength conversion element 30 to the amount of the fluorescent light 94. Therefore, when the light source device 102 is operated and the position of the condensing optical system 20 is deviated or the position of the wavelength conversion element 30 is deviated in the light source device 102, an error signal can be output to the outside. That is, this is because, when the position of the condensing optical system 20 or the wavelength conversion element 30 is deviated, the center of the irradiation position of the propagation light 82 is deviated from the first wavelength conversion portion 35 to the second wavelength conversion portion 36, and therefore, the color of the emitted light changes, and the detection in step (F) is possible. In this way, a slight failure state inside the light source device 102 can be detected by a combination of the difference in chromaticity coordinates of the light emitted from the first wavelength conversion section 35 and the second wavelength conversion section 36 and the signal processing from the plurality of photodetectors.

The light source device 102 can detect the ratio of the amounts of the propagating light 82 and the fluorescent light 94. Therefore, the first wavelength converting region 35 and the second wavelength converting region 36 are configured differently in terms of wavelength conversion efficiency, so that the center of the irradiation position of the propagating light 82 can be detected, and the first wavelength converting region 35 is shifted to the second wavelength converting region 36. Therefore, a slight failure state inside the light source device 102 can be detected.

When the light source device 102 is mounted with a plurality of photodetectors, for example, when a failure such as breakage of the wavelength conversion element 30 occurs, an error signal can be output from the light source device 102. For example, when the wavelength conversion element 30 is completely peeled off, chromaticity coordinates and wavelength conversion efficiency of the emitted light are greatly changed, and therefore, an error signal can be output based on a signal from the photodetector. In this case, according to an error signal output from the light source device 102, measures such as stopping the power applied to the light source device 102 by an external circuit or the like can be taken. As a result, the broken wavelength conversion element 30 can suppress the reflection of the propagating light 82 without scattering, and the propagating light 82 with high directivity can be continuously emitted to the outside.

The light source device of the present embodiment includes, in addition to the plurality of photodetectors, a wavelength conversion element having a second wavelength conversion portion 36 surrounding the first wavelength conversion portion 35 and its periphery. With this configuration, it is possible to detect a failure state such as a minute deviation of the wavelength conversion element before reaching a significant failure state such as complete peeling of the wavelength conversion element 30. Therefore, the operation of the light source device can be stopped in a failure state before the failure state such as the propagation light 82 having high directivity is emitted to the outside.

The light source device 102 according to the present embodiment may be used for a lighting device.

(modification 1 of example 4)

Next, the structure of the light source device 300 according to modification 1 of the present embodiment will be described with reference to fig. 22.

Fig. 22 is a schematic cross-sectional view showing a schematic configuration of a light source device 300 according to this modification.

The light source device 300 according to the present modification is characterized in that the first photodetector 25, the second photodetector 26, and the third photodetector 27, and the microcontroller 65 for calculating signals output from the respective photodetectors are incorporated. Further, each photodetector and the microcontroller 65 are mounted on a single printed circuit board 62.

In fig. 22, the semiconductor light emitting device 10, the condensing optical system 20, and the wavelength conversion element 30 are fixed to a case 50 made of, for example, an aluminum alloy. The case 50 further includes a cover member 61 for sealing the optical axes of the excitation light 81 and the propagation light 82. The cover member 61 is formed of glass, for example.

The semiconductor light emitting device 10 includes, for example, a semiconductor light emitting element 11 mounted on a package 13 that is a TO-CAN package.

The semiconductor light emitting device 10 is fixed such that excitation light is emitted from the semiconductor light emitting element 11 to the upper part in the figure. The package 13 is fixed so that the semiconductor light emitting element 11 is covered with the glass-fixed metal can 14.

The condensing optical system 20 includes a lens 20a and a reflective optical element 20b as a concave reflective surface, for example, in this modification. The reflective optical element 20b is fixed to the support member 53. The support member 53 is fixed to the housing 50 by a screw 56.

The wavelength conversion element 30 includes a support member 32, and a wavelength conversion portion 38 disposed on the support member 32. The wavelength conversion unit 38 includes a first wavelength conversion unit 35, and a second wavelength conversion unit disposed around the first wavelength conversion unit 35 when viewed from above on a surface of the support member 32 on which the wavelength conversion unit 38 is disposed. In the present embodiment, the wavelength conversion element 30 includes a reflecting member 31 formed between the support member 32 and the first wavelength conversion portion 35. In the light source device 300 according to the present modification, the structure of the wavelength conversion element 30 that can be used is not limited to the above-described structure. In the light source device 300, any wavelength conversion element can be used. For example, the wavelength conversion unit 38 may be provided with a single wavelength conversion member.

The wavelength conversion element 30 is fixed to the housing 50. Specifically, an adhesive layer (not shown in fig. 22) that is a metal film of Ti, au, or the like, for example, is formed on the surface of the support member 32 where the wavelength conversion portion 38 is not disposed. The adhesive layer is fixed to the case 50 by solder or the like, not shown.

Between the wavelength conversion element 30 and the reflection optical element 20b, for example, a separation optical element 21 that is glass with an antireflection film is arranged. A large part of the propagating light 82 from the reflective optical element 20b is transmitted through the separation optical element 21, and another part is reflected. Accordingly, a part of the propagating light 82 is separated by the separation optical element 21.

On the opposite side of the wavelength conversion element 30 to the direction in which the reflective optical element 20b is disposed, a reflective member 22, for example, glass forming a reflective surface, is fixed to the case 50. The reflecting member 22 is an optical member that guides the light radiated from the wavelength conversion element 30 to the first photodetector 25 and the second photodetector 26. In the present modification, the reflecting member 22 is disposed at a position where a portion of the light 95 emitted from the wavelength conversion element 30, which is not emitted to the outside, enters.

Pins 13a and 13b of semiconductor light emitting device 10 are connected to printed circuit board 62 on which first photodetector 25, second photodetector 26, third photodetector 27, and microcontroller 65 are mounted. The printed circuit board 62 is disposed at the lower portion of the case 50 and covered with the cover member 52. The first photodetector 25, the second photodetector 26, and the third photodetector 27 are mounted on the wavelength conversion element 30 side of the printed circuit board 62. A first photodetector 25 is disposed below the separation optical element 21, and a second photodetector 26 and a third photodetector 27 are disposed below the reflecting member 22.

On the printed circuit board 62, a connector 67 for connection with an external circuit is mounted. An external wiring 68 is mounted on the connector 67 and electrically connected to the outside.

The cover member 51 and the cover member 61, which is, for example, transparent glass with an antireflection film, are attached to the case 50 so as to cover the optical path of the propagating light 82. The cover member 51 is made of a metal material such as aluminum alloy, and is fixed to the housing 50 by a screw 55. The cover member 61 is disposed to cover an opening formed by the housing 50 and the cover member 51. The cover member 61 seals the optical path of the propagation light 82 from the outside, and emits the light 95 emitted from the wavelength conversion element 30 to the outside.

The case 50 has a reflection surface 50a for reflecting a part of the propagation light 82 on the light path of the propagation light 82 separated by the separation optical element 21. The first filter 23 and the second filter 24, which are optical filters, are mounted on the housing 50.

Work

Next, the operation of the light source device 300 will be described. The light emitted from the semiconductor light-emitting device 10 is converted into substantially parallel light by the lens 20a, and then converted into the propagation light 82 condensed by the reflective optical element 20b, and directed toward the wavelength conversion element 30. The propagating light 82 is transmitted through the separating optical element 21 before reaching the wavelength converting element 30. At this time, a part of the propagation light 82 is reflected by the reflection surface 50a formed in the case 50, and is incident on the third photodetector 27.

Most of the propagation light 82 incident on the wavelength conversion element 30 is incident on the first wavelength conversion portion 35 of the wavelength conversion element 30, and the other part of the propagation light 82 is incident on the second wavelength conversion portion 36. In the first wavelength converting region 35, a part of the light is converted into fluorescence 94, and a part of the light is scattered by the first wavelength converting region 35 to be scattered light 93, which is emitted from the wavelength converting element 30. The scattered light 93 and the fluorescent light 94 become the emitted light 95, and the transmitted hood member 61 is emitted from the light source device 300.

On the other hand, a part of the light 95 emitted from the wavelength conversion element 30 is reflected by the reflecting member 22 and directed to the first photodetector 25 and the second photodetector 26.

In the above configuration, the signals output from the first photodetector 25, the second photodetector 26, and the third photodetector 27 are calculated by the microcontroller 65 incorporated in the light source device 300 in the flow chart shown in fig. 21, and an error signal or a normal signal is output.

Further, an error signal and a normal signal are output to the outside through the connector 67. The error signal output to the outside is transmitted to an external circuit, not shown, and a safety measure such as stopping the application of power from the external circuit to the light source device 300 is adopted.

[ Effect ]

The light source device 300 of the above-described configuration incorporates the first photodetector 25, the second photodetector 26, and the third photodetector 27, and the microcontroller 65 for calculating signals output from these photodetectors. Further, in the light source device 300, the photodetectors and the microcontroller 65 are mounted on one printed circuit board 62. Accordingly, the signal of the light source device 300 is received, and information about the states of the propagating light 82, the wavelength conversion element 30, and the like is obtained. For example, it is possible to detect whether or not the propagation light 82 from the semiconductor light emitting device 10 is accurately incident on the wavelength conversion element 30.

Further, by disposing the photodetectors and the microcontroller 65 on one printed circuit board 62, the light source device 300 in which the photodetectors capable of detecting the transmitted light 82 and the emitted light 95 can be mounted can be realized with a simple structure. Further, in the light source device 300, the propagating light 82 is separated by the separation optical element 21 that is a glass with an antireflection film having a high transmittance, and therefore, optical loss accompanying detection of the propagating light 82 can be suppressed. In the light source device 300, since a part of the light emitted 95 that is not emitted from the cover member 61 of the light source device 300 is guided to the first photodetector 25 and the second photodetector 26 by the reflecting member 22, optical loss associated with the detection of the light emitted 95 can be suppressed.

Next, the luminance distribution and the color distribution of the light emitting region of the wavelength conversion element 30 of the light source device 300 according to the present modification will be described with reference to the drawings together with the comparative example.

Fig. 23 is a graph showing an example of measurement of the luminance distribution and the color distribution of the light emitting surface of the light source device according to the present modification and the comparative example.

Fig. 23 (e) and (f) are graphs showing examples of measurement of the luminance distribution and the color distribution of the light emitting surface (i.e., the surface on the light emitting side of the wavelength conversion portion 38) of the light source device 300 according to the present modification. Specifically, the first wavelength conversion portion 35 is formed by mixing YAG phosphor particles and Al ₂ O ₃ The ceramic phosphor is fixed on a support member in a square shape with a side length of 0.4mm and a thickness of 70 μm. Further, for the second wavelength converting region 36, a converting region formed around the first wavelength converting region 35 in which YAG phosphor particles having an average particle diameter of 2 μm are mixed in silsesquioxane was used.

On the other hand, fig. 23 (a) and (b) show the luminance distribution and the color distribution measured by the wavelength conversion element according to the comparative example, which is constituted by the wavelength conversion unit 38 having the identical configuration of the first wavelength conversion unit 35 and the second wavelength conversion unit 36 (that is, constituted by only the first wavelength conversion unit 35), respectively. Specifically, the wavelength conversion portion 38 is formed on the support member by mixing YAG phosphor particles having an average particle diameter of 8 μm with silsesquioxane, and having a thickness of 30 μm and a width of 1mm or more.

Fig. 23 (c) and (d) show the luminance distribution and the color distribution measured by the wavelength conversion element according to the comparative example, which is made of only a scattering member, without using a phosphor material, as the material constituting the second wavelength conversion portion 36. At this time, as for the specific structure of the second wavelength converting region 36, tiO having an average particle diameter of 2 μm was used ₂ Particles mixed in silsesquioxaneIs a structure of (a). The first wavelength converting region 35 was a square with an outer shape having a side length of 0.4mm and a thickness of 70 μm, as in the present modification.

As shown in fig. 23 (e), in the light source device 300, a uniform luminance distribution with high luminance in the center portion can be realized. In fig. 23 (e), a region with a high luminance distribution (a region within 0.2mm from the center) corresponds to the first surface 35a (first emission region 41) of the first wavelength converting region 35 of the wavelength converting element 30, and a region around the region corresponds to the first surface 36a (second emission region 42) of the second wavelength converting region 36 (refer to fig. 2A and the like for the first surfaces 35a and 36a, and the first emission region 41 and the second emission region 42). In this way, in the light source device 300, a luminance distribution having a high contrast between the first emission region 41 and the second emission region 42 can be obtained. Further, as shown in the color distribution of fig. 23 (f), the distribution of the chromaticity coordinates x of the first emission region 41 and the distribution of the chromaticity coordinates x of the second emission region 42 are both distributed between the coordinates 0.2 to 0.4.

On the other hand, as shown in fig. 23 (c) and (d), when the second wavelength converting region 36 is formed without using a phosphor material, a uniform luminance distribution with high luminance in the center portion can be achieved, but blue light emission with chromaticity coordinates x of less than 0.2 occurs from the peripheral region. Further, in the case where the wavelength conversion element is constituted by only the first wavelength conversion portion, as shown in fig. 23 (a) and (b), white light emission can be realized in the entire region of the light emission region, but a luminance distribution having a uniform distribution region cannot be realized.

As described above, in the light source device according to the present modification, the luminance distribution in which the luminance is uniform in the central portion and high and the luminance in the peripheral portion is low can be realized, and white light emission can be performed in the entire light emission region.

The light source device 300 according to the present modification may be used for a lighting device.

(modification 2 of example 4)

Next, a light source device according to modification 2 of the present embodiment will be described with reference to fig. 24.

Fig. 24 is a schematic cross-sectional view showing a schematic configuration of a light source device 102A according to the present modification.

The light source device 102A shown in fig. 24 is a device in which the separation optical element 21, the first photodetector 25, the second photodetector 26, the third photodetector 27, the separation optical element 21, the first filter 23, and the second filter 24 are further disposed in the light source device 101 according to the modification of the embodiment 2 shown in fig. 13.

The separation optical element 21 is an element for guiding a part of light from the propagation light 82 to the other optical path 82 d.

The semiconductor light emitting device 10 is fixed such that the light emitted from the semiconductor light emitting element 11 is emitted to the wavelength conversion element 130. The excitation light 81 emitted from the semiconductor light emitting device 10 is emitted to the condensing optical system 20. The condensing optical system 20 condenses the excitation light 81 emitted from the semiconductor light emitting device 10 and having an emission angle in the horizontal direction and the vertical direction, and generates the propagation light 82 that is the excitation light that propagates spatially while being collimated or condensed to the wavelength conversion element 130. The propagation light 82 propagates along the central axis 82i and irradiates the wavelength conversion element 130.

The propagating light 82 is transmitted through the separating optical element 21 before reaching the wavelength converting element 130. At this time, a part of the propagation light 82 is reflected and enters the third photodetector 27.

Most of the propagation light 82 incident on the wavelength conversion element 130 enters the first wavelength conversion portion 35 of the wavelength conversion element 130, and the other part of the propagation light 82 enters the second wavelength conversion portion 36.

In the first wavelength converting region 35, a part of the light is converted into fluorescence 94, and the other part of the light is scattered by the first wavelength converting region 35 to be scattered light 93, which is emitted from the wavelength converting element 130. The scattered light 93 and the fluorescent light 94 become the emitted light 95, and are emitted from the light source device 300.

On the other hand, a part of the light 95 emitted from the wavelength conversion element 130 passes through the reflecting member 31, the supporting member 32, and the antireflection film 33, and is emitted to the opposite side (lower side in fig. 24) of the wavelength conversion element 130 from the surface on which the first wavelength conversion portion 35 is formed. And is guided to the first photodetector 25 and the second photodetector 26. At this time, the light 95 emitted toward the first photodetector 25 enters the first filter 23. The light 95 emitted toward the second photodetector 26 enters the second filter 24.

In this configuration, the light guided to the first photodetector 25, the second photodetector 26, and the third photodetector 27 is photoelectrically converted and then input to a microcontroller not shown, and this operates in the same manner as the light source device 102 according to embodiment 4.

As in the present modification, the light source device 102A in which the incident surface of the excitation light (the propagation light 82) and the surface from which the emitted light 95 is emitted are disposed on opposite sides of the wavelength conversion element 130 can be easily diagnosed as to the state of the light source device 102A. For example, the change in color of the light emitted 95 from the wavelength conversion unit 38 can be easily detected. More specifically, for example, the irradiation position of the propagation light 82 (excitation light) can be detected, and the state such as the case where the propagation light is deviated from the first wavelength converting region 35 to the second wavelength converting region 36 can be detected.

The light source device 102A according to the present modification may be used for a lighting device.

(light Source device of example 5)

Next, a light source device according to example 5 will be described. The wavelength conversion element for a light source device according to the present embodiment is different from the wavelength conversion element according to each of the above embodiments in that a concave portion is formed on the first wavelength conversion portion 35 side of the reflecting member, and the first wavelength conversion portion 35 is disposed on the bottom surface of the concave portion. Therefore, a part or all of the side surface of the first wavelength converting region 35 is surrounded by the reflecting member 31. Hereinafter, the light source device according to the present embodiment will be described with reference to the drawings, focusing on the differences from the wavelength conversion element 30 of the light source device according to embodiment 1.

Fig. 25 is a schematic cross-sectional view showing a schematic configuration of the wavelength conversion element 330 according to the present embodiment.

In the wavelength conversion element 330 shown in fig. 25, for example, a concave portion is formed on the surface of the support member 32r composed of an aluminum plate or an aluminum alloy plate by a metal working or forging method. Accordingly, in the present embodiment, the support member 32r also functions as a reflecting member. In the concave portion, for example, a first wavelength conversion portion 35 in which phosphor particles composed of YAG phosphor particles and a transparent bonding material composed of silsesquioxane are mixed is arranged. The second wavelength converting region 36 is disposed so as to surround the first wavelength converting region 35. Therefore, the side surface 35c of the first wavelength converting region 35 includes a side surface 135c that is an interface between the first wavelength converting region 35 and the support member 32r that functions as a reflecting member, and a side surface 235c that is an interface between the first wavelength converting region 35 and the second wavelength converting region 36.

Next, the function of the wavelength conversion element 330 according to the present embodiment will be described with reference to fig. 26.

Fig. 26 is a schematic cross-sectional view showing the function of the wavelength conversion element 330 according to the present embodiment.

The incident light 82a incident on the first wavelength converting region 35 is reflected multiple times inside the first wavelength converting region 35. At this time, the incident light 82a is reflected at the second surface 35b, the side surface 135c, and the side surface 235c of the first wavelength converting region 35, and becomes incident light 85a reflected multiple times. The incident light 85a is wavelength-converted by the first wavelength converting region 35 and becomes fluorescence 86a, which is also reflected a plurality of times. As a result, the light beam 91 composed of the scattered light 93a and the fluorescent light 94a is emitted from the first wavelength conversion portion 35. At this time, the scattered light 93a and the fluorescent light 94a are reflected multiple times in the first wavelength converting region 35, and the light distribution in the first wavelength converting region 35 can be made uniform. The second surface 35b and the side surface 135c of the first wavelength converting region 35 are formed at the interface with the support member 32r functioning as a reflecting member. Therefore, the reflectance of the incident light 85a and the fluorescence 86a on the second surface 35b and the side surface 135c can be improved.

Therefore, light with high brightness can be emitted from the first wavelength converting region 35.

(modification of example 5)

Next, a light source device according to a modification of the present embodiment will be described with reference to the drawings. The wavelength conversion element for a light source device according to the present modification is mainly different from the wavelength conversion element 330 according to embodiment 5 in the structure of the support member. Hereinafter, the wavelength conversion element according to the present modification will be described with reference to the drawings, focusing on the differences from the wavelength conversion element 330 according to embodiment 5.

Fig. 27 is a schematic cross-sectional view showing a schematic configuration of a wavelength conversion element 330A used in the light source device according to the present modification.

As shown in fig. 27, the wavelength conversion element 330A includes a support member 32 and a reflecting member 31 disposed on the support member 32. The first wavelength conversion unit 35 is a block-shaped wavelength conversion member, such as a ceramic YAG phosphor, having irregularities formed on the surface thereof.

In the present modification, for example, a silicon substrate having a (100) main surface is used for the support member 32. At the center of the support member 32, a recess is formed by photoresist pattern formation based on semiconductor lithography and anisotropic wet etching based on tetramethylammonium hydroxide (TMAH). According to this structure, the inclined surface of the concave portion can be accurately formed at a predetermined angle, and the depth of the concave portion can be accurately controlled. Further, a reflective member 31, which is a metal film made of, for example, chromium, aluminum, or the like, is formed in the concave portion.

Next, the bottom 32b of the recess is coated with a bonding material 34 of a silicone resin in a solution form, for example, at the time of coating. The first wavelength converting region 35 in the form of a block is attached to the bonding material 34 from above the recess by a vacuum chuck or the like, not shown.

Next, the bonding material 34 is cured in a high temperature atmosphere, for example, at about 150 ℃, and the first wavelength converting region 35 is fixed to the concave portion.

Next, a second wavelength converting region 36 is formed around the first wavelength converting region 35. Specifically, by coating the second wavelength converting region 36 in a paste form in which phosphor particles having a predetermined average particle diameter are mixed with a transparent bonding material and assimilating the mixture, the second wavelength converting region 36 can be easily formed.

According to this structure, the wavelength conversion element 330A that can obtain the same effects as those of the wavelength conversion element according to each of the embodiments described above can be realized. Further, in the wavelength conversion element 330A, since the concave portion is provided in the support member 32 and the first wavelength conversion portion 35 is attached to the concave portion, the first wavelength conversion portion 35 can be accurately fixed to an appropriate position on the support member 32.

Example 6

Next, a light source device according to example 6 will be described. The wavelength conversion element for a light source device according to the present embodiment is different from the wavelength conversion element 230 according to embodiment 3 in that a reflecting member different from the second wavelength conversion unit 36 is provided between the first wavelength conversion unit 35 and the support member 32, and surrounds at least a part of the second surface 35b and the side surface 35c of the first wavelength conversion unit 35. Hereinafter, the light source device according to the present embodiment will be described with reference to the drawings, focusing on the differences from the wavelength conversion element 230 of the light source device according to embodiment 3.

Fig. 28 is a schematic cross-sectional view showing a schematic structure of a wavelength conversion element 430 used in the light source device according to the present embodiment.

As shown in fig. 28, the wavelength conversion element 430 according to the present embodiment includes, between the first wavelength conversion portion 35 and the support member 32, a reflection member 31 different from the second wavelength conversion portion 36 surrounding at least a part of the second surface 35b and the side surface 35c of the first wavelength conversion portion 35. As the reflecting member 31, a scattering member in which high refractive index particles are dispersed can be used. According to this configuration, the scattering member covering the lower surface and the side surfaces of the first wavelength converting region 35 is not limited to the second wavelength converting region 36, and therefore, the degree of freedom in the configuration of the scattering member can be improved.

The reflective film 32a formed of a dielectric multilayer film, a metal reflective film, or the like may be formed on the main surface of the support member 32 where the first wavelength conversion region 35 is disposed. For example, a film made of Ag or the like can be used for the reflective film 32a. According to this structure, even if the thickness of the reflecting member 31 between the first wavelength converting region 35 and the supporting member 32 is made thin, the incident light 85a from the first wavelength converting region 35 toward the supporting member 32 can be efficiently reflected by the double reflecting structure of the reflecting member 31 and the reflecting film 32a. Further, even when a transparent bonding material having low thermal conductivity is used as a structural material of the reflecting member between the first wavelength converting region 35 and the supporting member 32, the thickness of the reflecting member 31 can be reduced, and therefore, heat generated in the first wavelength converting region 35 can be efficiently discharged to the supporting member 32. In the above configuration, the thickness of the reflecting member 31 between the first wavelength converting region 35 and the supporting member 32 is preferably 1 μm or more and 50 μm or less.

[ method for manufacturing wavelength conversion element according to example 6 ]

Next, a method for manufacturing the wavelength conversion element 430 according to embodiment 6 will be described with reference to the drawings.

Fig. 29 is a schematic cross-sectional view showing each step of the method for manufacturing the wavelength conversion element 430 according to the present embodiment.

First, as shown in a sectional view (a) of FIG. 29, for example, on a support member 32 as a silicon substrate, for example, tiO having an average particle diameter of between 0.1 μm and 4 μm is coated ₂ A pasty reflecting member 31 in which particles are mixed in a transparent bonding material. In this case, for example, a paste-like transparent bonding material in which silsesquioxane is dissolved in an organic solvent is used as the transparent bonding material. Further, the first wavelength converting region 35 is held by the vacuum chuck 150.

Next, as shown in a cross-sectional view (b) of fig. 29, the first wavelength converting region 35 is disposed on the pasty reflecting member 31. At this time, the reflective member 31, which is pasty due to the intermolecular force of the first wavelength converting region 35 and the transparent bonding material, rises on the side surface of the first wavelength converting region 35. Therefore, the paste-like reflecting member 31 can be easily covered, and at least a part of the lower surface and the side surface of the first wavelength converting region 35 can be easily covered.

Then, heating is performed to cure the reflecting member 31.

At this time, for example, the organic solvent of the pasty reflecting member 31 is volatilized and cured by heating at approximately 150 ℃ for approximately two hours.

Next, as shown in a cross-sectional view (c) of fig. 29, the second wavelength converting region 36 is arranged so as to surround the periphery of the first wavelength converting region 35.

At this time, for the second wavelength converting region 36, for example, a paste-like wavelength converting member in which phosphor particles having particle diameters of 1 μm to 4 μm are mixed in a transparent bonding material is used. Here, the particle diameter distribution of 1 μm to 4 μm means that the average particle diameter D50 is 2 μm, D10 is 1 μm, and D90 is 4 μm. In this case, for example, a paste-like transparent bonding material in which silsesquioxane is dissolved in an organic solvent is used as the transparent bonding material.

The second wavelength converting region 36 is coated, for example, by a syringe. The second wavelength converting region 36 can be formed around the first wavelength converting region 35. At this time, the pasty second wavelength converting region 36 is contracted, and therefore, irregularities along the phosphor particles can be easily formed on the surface of the second wavelength converting region 36. Accordingly, the propagation light 82 can be scattered on the surface of the second wavelength converting region 36.

By the above manufacturing method, the wavelength conversion element 430 of the light source device according to the present embodiment can be easily manufactured.

(modification 1 of example 6)

Next, a wavelength conversion element for a light source device according to a modification of the present embodiment will be described.

In the wavelength conversion element according to the present modification, a substrate having irregularities formed on the surface thereof is used as a support member. Further, a reflective film is formed on the uneven surface of the support member. Hereinafter, a wavelength conversion element for a light source device according to this modification will be described with reference to the drawings.

Fig. 30 is a schematic cross-sectional view showing a schematic configuration of a wavelength conversion element 430A for a light source device according to this modification.

As shown in fig. 30, in the wavelength conversion element 430A according to the present modification, according to the above-described configuration, even when the first wavelength conversion portion 35 and the reflection member 31 are separated from the support member 32 in the wavelength conversion element 30, the incident light 82a and 82b is scattered on the uneven surface of the support member 32, and therefore, the light source device using the wavelength conversion element 30 can safely handle the light.

Further, as shown in fig. 30, it is preferable that the first surface 35a, the second surface 35b, and the side surface 35c of the first wavelength converting region 35 have irregularities having a surface roughness Ra of 0.5 μm to 5 μm, for example. Since the incident light 85a and the fluorescent light 86a are reflected and scattered by the irregularities in the first wavelength conversion portion 35a plurality of times, the luminance distribution in the plane of the outgoing light 91 emitted from the first emission region can be made more uniform. Further, the irregularities of the first surface 35a can scatter and reflect a part of the incident light 82a when the first surface 35a is reflected, and therefore, the luminance distribution with respect to the emission direction of the emitted light 91 can be made more uniform.

As shown in fig. 30, an intermediate layer 331 including an absorbing member may be provided between the reflecting member 31 and the second wavelength converting region 36. As the absorbing member, a member in which metal fine particles such as gold, carbon fine particles, europium-activated phosphor particles, and the like are mixed in a transparent bonding material can be used. With this configuration, the incident light 82b can be suppressed from passing through the second wavelength conversion region 36, reaching the reflecting member 31, and being reflected. Therefore, the wavelength conversion efficiencies of the first wavelength converting region 35 and the second wavelength converting region 36 can be designed more freely.

(variations 2 to 4 of example 6)

Next, the wavelength conversion element for a light source device according to modification examples 2 to 4 of the present embodiment will be described with reference to the drawings. Each modification example is different from the wavelength conversion element 430 according to the present embodiment in the structure of the main reflecting member 31 and the second wavelength conversion portion 36.

Fig. 31A is a schematic cross-sectional view showing a schematic configuration of a wavelength conversion element 430B for a light source device according to modification 2 of the present embodiment. Fig. 31B is a schematic cross-sectional view showing a schematic configuration of a wavelength conversion element 430C for a light source device according to modification 3 of the present embodiment. Fig. 31C is a schematic cross-sectional view showing a schematic configuration of a wavelength conversion element 430D for a light source device according to modification 4 of the present embodiment.

In the wavelength conversion element 430B according to modification 2 shown in fig. 31A, the reflection member 31 reaches the uppermost portion of the side surface 35c of the first wavelength conversion portion 35. According to this configuration, the wavelength conversion efficiency of the first wavelength converting region 35 can be improved.

In the wavelength conversion element 430C according to modification 3 shown in fig. 31B, the reflecting member 31 covers a part of the side surface 35C of the first wavelength converting region 35. The second wavelength converting region 36 covers a part of the side surface of the first wavelength converting region 35. According to this configuration, at least a part of the side surface 35c of the first wavelength converting region 35 is covered with the radiation member 31, so that the conversion efficiency of the first wavelength converting region 35 can be improved. In such a configuration wavelength conversion element 430C, the thickness of the second wavelength conversion portion 36 can be made thin with respect to the thickness of the first wavelength conversion portion 35. Therefore, the wavelength conversion efficiency of the second wavelength converting region can be easily reduced relative to that of the first wavelength converting region.

In the wavelength conversion element 430D according to modification 4 shown in fig. 31C, the reflecting member 31 reaches the uppermost portion of the side surface of the first wavelength converting region 35. The second wavelength converting region 36 covers an edge portion of the first surface 35a of the first wavelength converting region 35. In other words, the portions of the first wavelength converting region 35 other than the central portion of the first surface 35a are covered with the second wavelength converting region 36. In the wavelength conversion element 430D having such a configuration, the incident light 85a reflected multiple times by the first wavelength converting region 35 is reflected not only by the side surface 35c and the second surface 35b but also by a part of the first surface 35a, and therefore, the wavelength conversion efficiency of the first wavelength converting region 35 can be improved. In this case, the thickness of the second wavelength converting region 36 on the first wavelength converting region 35 is set to be smaller than the thickness of the first wavelength converting region 35. Preferably, the number is half or less. According to such a configuration, the light 91 emitted from the first wavelength converting region 35 can be emitted through the second wavelength converting region 36 on the first wavelength converting region 35, and therefore, the uniformity of the luminance distribution in the central portion of the light emitting region of the wavelength converting element 230A can be improved.

(light Source device of example 6)

Next, a specific example of the light source device according to the present embodiment will be described with reference to the drawings.

Fig. 32 is a cross-sectional view schematically showing the schematic structure of a light source device 400 according to the present embodiment.

As shown in fig. 32, the light source device 400 includes the semiconductor light emitting device 10, the holder 54, the lenses 20a and 20d, the optical fiber 20c, the housing 50, the heat radiation mechanism 70, and the wavelength conversion element 430.

As shown in fig. 32, the semiconductor light emitting device 10 is held by a holder 54 together with the lens 20 a. The wavelength conversion element 430 is fixed to the case 50 and covered with the lens 20d and the transparent cover member 61 a. The case 50 is attached to the heat radiating member 75 via the heat radiating mechanism 70. Here, the heat dissipation mechanism 70 is a mechanism that promotes dissipation of heat generated in the case 50. For the heat dissipation mechanism 70, a peltier element or the like can be used, for example. With such a configuration, heat generated in the wavelength conversion element 430 can be efficiently discharged.

The excitation light 81 emitted from the semiconductor light emitting element 11 of the semiconductor light emitting device 10 is converted into the propagation light 84 converged at one end portion of the optical fiber 20c by the lens 20a, and is incident on the optical fiber 20c. The propagation light 84 incident on the optical fiber 20c propagates through the optical fiber 20c, and is emitted as propagation light 85 from the other end of the optical fiber 20c. The propagation light 85 is converged by the lens 20d and irradiates the first wavelength converting region 35 and the second wavelength converting region 36 of the wavelength converting element 430. At this time, the light intensity of the propagation light 82 on the incidence surface of the wavelength conversion element 430 has a continuous distribution in which the incidence surface of the first wavelength conversion portion 35 is strong and the incidence surface of the second wavelength conversion portion 36 on the periphery thereof is weak. The light is emitted from the first surface of the first wavelength converting region 35 as light-scattered light scattered by the propagating light 82 and light-emitted light 91 obtained by mixing the light-scattered light with fluorescence generated after the wavelength conversion of the propagating light 82. The light emitted from the first surface of the second wavelength converting region 36 is mixed with the scattered light, which is light scattered by the propagating light 82, and the fluorescence generated after the wavelength conversion of the propagating light 82, and is emitted light 92.

According to the above configuration, white light having a high contrast in light emission distribution can be emitted from the wavelength conversion element 430 of the light source device 400. Further, according to the above-described configuration, the holder 54 of the semiconductor light-emitting device 10 to which the heating element is fixed and the case 50 to which the wavelength conversion element 430 that generates heat by irradiation of the propagating light 82 is fixed can be thermally separated. Accordingly, in the light source device 400, the temperature rise of the first wavelength converting region 35 can be suppressed, and therefore, the reduction in conversion efficiency associated with the temperature rise of the first wavelength converting region 35 can be suppressed, and light having higher brightness can be emitted.

Example 7

Next, a light source device according to example 7 will be described. The wavelength conversion element for a light source device according to the present embodiment is different from the wavelength conversion element according to the respective embodiments described above in that the wavelength conversion element has a plurality of first wavelength converting portions 35. Hereinafter, a light source device according to the present embodiment will be described with reference to the drawings.

Fig. 33 is a schematic cross-sectional view showing a schematic structure of a wavelength conversion element 530 for a light source device according to the present embodiment. Fig. 34 is a schematic oblique view showing the structure and operation outline of the light source device 500 according to the present embodiment.

As shown in fig. 33, the wavelength conversion element 530 according to the present embodiment includes a plurality of first wavelength conversion portions 35. The plurality of first wavelength converting regions 35 are fixed to the main surface of the support member 32. Although not shown in fig. 33, a reflecting member may be disposed between the support member 32 and the plurality of first wavelength converting regions 35. The second wavelength converting regions 36 are disposed around each of the plurality of first wavelength converting regions 35.

The first emission region 41 is formed on the surface of the first wavelength converting region 35 on the side where the propagating light 82 enters, and the second emission region 42 is formed on the surface of the second wavelength converting region 36 on the side where the propagating light 82 enters.

In the present embodiment, a case where seven first wavelength converting regions 35 are arranged will be described.

First, a method of manufacturing the wavelength conversion element 530 and a structure thereof according to the present embodiment will be described.

First, for example, the surface of the support member 32 made of an aluminum plate or the like is fixed with an adhesive, not shown, in a state where seven first wavelength conversion portions 35, which are ceramic YAG phosphors, are arranged with a predetermined gap therebetween. For example, the second wavelength converting region 36 in the form of a paste in which phosphor particles are mixed in the solution-like transparent bonding material is filled in the gap between the first wavelength converting regions 35 and cured. At this time, the second wavelength converting region 36 is also formed in the periphery of the first wavelength converting region 35 disposed at the outermost periphery among the plurality of first wavelength converting regions 35.

In the manufacturing process, for the support member 32, a plate-like member having a square shape with a side length of 3mm to 5mm and a thickness of 0.1mm to 0.5mm is used.

For the first wavelength converting region 35, for example, a square having an outer shape of 0.2mm to 0.6mm in side length and a ceramic YAG phosphor having a thickness of 0.03mm to 0.1mm is used.

The gap between two adjacent first wavelength converting regions 35 is set to, for example, 0.05mm to 0.2mm.

For the second wavelength converting region 36, for example, YAG phosphor particles having a particle diameter of 0.5 to 5 μm as an average particle diameter D50 are mixed with a transparent bonding material having a refractive index of 1.5 or less, such as silsesquioxane or silicone resin. As described above, by using phosphor particles having a small particle diameter and a transparent bonding material having a large refractive index difference from the phosphor particles, the reflectance with respect to excitation light (propagation light) can be made higher than that of the first wavelength converting region 35.

The wavelength conversion element 530 shown in fig. 33 is configured by the above-described manufacturing method.

The case of fig. 33 from the left third first wavelength converting region 35, in which only the propagation light 82 is irradiated to the vicinity of the plurality of first wavelength converting regions 35 of the wavelength converting element 530 having the above-described structure, will be described.

In this case, regarding the propagation light 82, most of the propagation light 82 is irradiated to the first face 35a of the first wavelength converting region 35 and the first faces 36a of the second wavelength converting regions 36 at both ends thereof. At this time, a part of the propagation light 82 incident on the first wavelength converting region 35 from the first surface 35a is reflected multiple times on the second surface 35b and the side surface 35c inside the first wavelength converting region 35, and the light intensity distribution becomes uniform in the first wavelength converting region 35. A part of the propagating light 82 is absorbed by the phosphor of the first wavelength converting region 35 to become fluorescence. The fluorescence is also reflected on the second surface 35b and the side surface 35c inside the first wavelength converting region 35a multiple number of times, similarly to the propagation light 82, and the light intensity distribution becomes uniform in the first wavelength converting region 35. The light 91, which is a mixed light of the light transmitted through the multiple reflection and having a uniform light intensity distribution (scattered light) and the fluorescence, is emitted from the first emission region 41. On the other hand, the propagation light entering the second wavelength converting region 36 around the first wavelength converting region 35 becomes the output light 92, which is the mixed light of the propagation light (scattered light) scattered by the second wavelength converting region 36 and the fluorescence, and is output from the second output region 42.

Here, the second wavelength converting region 36 is lower than the first wavelength converting region 35 with respect to the intensity ratio of fluorescence to scattered light. That is, the conversion efficiency of the transmitted light 82 into fluorescence per unit amount of incident light of the first surface 36a is smaller than that of the first surface 35 a.

As a result, in the vicinity of the third first wavelength conversion portion 35 from the left in fig. 33, the emitted light having a uniform light intensity distribution can be emitted from the first emission region 41. At this time, the light emitted from the second emission region 42 has a low light intensity and has a spectrum of emitted light in which the spectrum of the propagating light and the spectrum of the fluorescent light are mixed.

Therefore, the white light with uniform and high brightness 91 can be emitted from the entire first emission region 41 of the third first wavelength converting region 35 from the left side in fig. 33, and the white light with low brightness 92 can be emitted from the second wavelength converting region 36 around the white light. That is, the light emitted from the wavelength conversion element 530 can be emitted with sharp edges of the light intensity distribution and with a small color distribution. The light intensity distribution and the color distribution can be realized in accordance with the positions of the plurality of first wavelength converting regions 35 even when the irradiation positions of the propagating light 82 are changed. That is, by changing the irradiation position of the propagation light 82, white light having sharp edges of the light intensity distribution of the emission surface can be emitted from each of the plurality of different first wavelength converting regions 35. That is, the first wavelength conversion portion 35 corresponding to the emission position of the emitted light having the sharp edge of the emitted light intensity distribution on the emission surface can be selected.

Further, in the present embodiment, the irradiation position of the propagation light 82 is moved in the two-dimensional direction, and the light emission position of the emitted light can be moved in the two-dimensional direction.

Such a shift in the light emission position in the two-dimensional direction can be achieved by arranging a plurality of first wavelength converting regions 35 of the wavelength converting element 530 in one direction and a plurality of first wavelength converting regions 35 in a direction perpendicular to the one direction, that is, in a matrix.

For example, the light source device 500 in which the first wavelength converting units 35 of the wavelength conversion element 530 shown in fig. 33 are arranged in the left-right direction of the drawing, and three are arranged in the direction perpendicular to the drawing, and the wavelength conversion element 530 is mounted on the light source device 500 will be described with reference to fig. 34.

The light source device 500 includes a wavelength conversion element 530, a semiconductor light emitting device 10, a lens 20a, and a reflective optical element 20b having a mirror portion movable by electromagnetic force, for example. The wavelength conversion element 530, the semiconductor light emitting device 10, the lens 20a, and the reflective optical element 20b are fixed to the housing 50.

In the light source device 500, the semiconductor light emitting device 10 is electrically connected to a semiconductor light emitting device driving section capable of supplying current pulses in response to an instruction from an electronic control unit (Electric Control Unit), for example. The reflective optical element 20b is electrically connected to a reflective optical element driving section capable of supplying electric power of an arbitrary waveform in response to an instruction from the electronic control unit. Further, on the emission side of the wavelength conversion element 530, for example, a light projecting member 120 as a projection lens is arranged.

When power is supplied from the semiconductor light emitting device driving section, the semiconductor light emitting device 10 emits excitation light 81. The excitation light 81 is transmitted light 82, which is the parallel light or the condensed light, by the lens 20a, and enters the reflective optical element 20b. At this time, the reflective optical element 20b is set to an arbitrary angle according to the electric power from the reflective optical element driving section. Accordingly, the propagation light 82 can be irradiated to an arbitrary position of the wavelength conversion element 530. Here, it is assumed that the plurality of first wavelength converting portions 35 of the wavelength converting element 530 are arranged in a matrix of seven columns in the horizontal direction and three rows in the vertical direction in fig. 34.

The propagation light 82 is irradiated to the surface of the wavelength conversion element 530 while being scanned from the upper left side to the upper right side (first row), from the left center side (i.e., left side and upper and lower direction center) to the right center side (i.e., right side and upper and lower direction center) (second row), and from the lower left side to the lower right side (third row) as shown by an arrow X and an arrow Y in the figure by the reflection optical element 20b, for example, as seen from the back surface side of the wavelength conversion element 30. At this time, a current from the semiconductor light emitting device driving section is applied to the semiconductor light emitting device 10, whereby, for example, in the first row, the first and second columns from left, the second row, the first, second, third, and seventh columns from left, and in the third row, the propagation light 82 is sequentially irradiated from the second to seventh columns from left. Accordingly, the projection image 99, which is a light projection pattern corresponding to the light emission pattern 112 of the light emission region, formed on the surface of the wavelength conversion element 530 is projected onto the irradiation section by the light projection member 120.

At this time, the projection image 99 is constituted by a projection image 99a of a plurality of projection patterns having sharp edges as light intensity distribution. Here, the projection image 99a is a projection image corresponding to the plurality of first wavelength converting regions 35 that emit light. Further, between two adjacent projection images 99a, a white projection image 99b having a weak light intensity is projected from the second wavelength conversion unit 36. In addition, an edge corresponding to the light intensity distribution of the light emitted 91 from the first wavelength converting region 35 is formed at an end portion of the projected image 99a corresponding to the first wavelength converting region 35 that emits light.

Therefore, with the light source device according to the present embodiment, white light having a high contrast of light emission distribution can be emitted, and the projection image 99 having an arbitrary light projection pattern can be projected.

Further, since white light having chromaticity coordinates close to or identical to those of the first wavelength converting regions 35 can be projected from the gaps of the plurality of first wavelength converting regions 35, projection light having a small color distribution can be projected.

(modification of example 7)

Next, a light source device according to a modification of embodiment 7 will be described with reference to fig. 35.

Fig. 35 is a schematic cross-sectional view showing a schematic configuration of a wavelength conversion element 530A for a light source device according to this modification.

In the present modification, the plurality of first wavelength converting regions 35 are fixed to the support member 32 as a silicon substrate, for example. At this time, the reflecting member 31 is disposed between the plurality of first wavelength converting regions 35 and the supporting member 32. For the reflecting member 31, for example, tiO having an average particle diameter D50 of between 10nm and 3 μm can be used ₂ And a member in which particles having a high refractive index are mixed in a transparent bonding material such as silsesquioxane or silicone resin.

At this time, the reflecting member 31 may cover a part of the bottom surface and the side surface of the first wavelength converting region 35.

According to this configuration, the propagation light 82 incident on the first surface 35a of the first wavelength converting region 35 is reflected multiple times on the second surface 35b and the side surface 35c of the first wavelength converting region 35, but the reflecting member 31 is formed on at least a part of the second surface 35b and the side surface 35 c. Therefore, the reflectance with respect to the second surface 35b and the side surface 35c of the first wavelength converting region 35 of the propagating light 82 can be improved, and the propagating light 82 can be efficiently scattered, and therefore, the light intensity distribution in the propagating light 82 and the first wavelength converting region 35 of the fluorescence can be made uniform with high efficiency. Therefore, according to the light source device including the wavelength conversion element 530A according to the present embodiment, white light having a high contrast of the emission distribution can be emitted.

Example 8

Next, a light source device according to embodiment 8 will be described with reference to fig. 36.

Fig. 36 is a schematic cross-sectional view showing the structure and function of the light source device 104 according to the present embodiment.

As shown in fig. 36, the light source device 104 according to the present embodiment includes the semiconductor light emitting device 10, the condensing optical system 20, the wavelength conversion element 130, the housing 50, and the second housing. The light source device 104 further includes a printed circuit board 62 on which the microcontroller 65, the first photodetector 25, the second photodetector 26, the connector 67, and the like are mounted.

In the light source device 104 according to the present embodiment, similar to modification 2 of embodiment 2 and modification 2 of embodiment 4, different phosphor materials are used for the first wavelength conversion portion 35 and the second wavelength conversion portion 36 of the wavelength conversion element 130. The support member 32 of the wavelength conversion element 130 is made of a material transparent to the propagation light 82, and the propagation light 82 enters from the support member 32 side of the wavelength conversion element 130.

In the present embodiment, the condensing optical system 20 is provided in the semiconductor light emitting device 10. The semiconductor light emitting device 10 and the wavelength conversion element 130 are fixed to the housing 50, and constitute a light source device 103 similar to the light source device 101 according to the modification of embodiment 2. Further, in the present embodiment, the housing 50 is fixed to the second housing 57. The semiconductor light emitting device 10 is connected to a printed circuit board 62 on which the microcontroller 65 and the first photodetector 25 are mounted, and the printed circuit board 62 is fixed to the second case 57, thereby constituting the light source device 104.

The semiconductor light emitting device 10 includes, for example, a semiconductor light emitting element 11 as a nitride semiconductor laser, and a package 13 to which the semiconductor light emitting element 11 is fixed. The package 13 includes a disk-shaped base and a pillar, and leads 13a and 13b are mounted on the base. The base and the column are made of, for example, oxygen-free copper. Pins 13a and 13b are fixed to the base via a washer 13g and an insulating member.

The condensing optical system 20 is, for example, a lens. In the present embodiment, the condensing optical system 20 is fixed to the base of the package 13 by the metal can 14. At this time, the metal can 14 is fixed to a welding table 13h formed on the base.

The case 50 is a base made of metal such as aluminum alloy, for example, and has a through hole in the center. The semiconductor light emitting device 10 is fixed to one surface of the case 50 connected to the through hole. The wavelength conversion element 130 is fixed to the other surface of the housing 50 connected to the through hole. As described above, the light source device 104 having the optical system substantially similar to the modification example of embodiment 2 shown in fig. 13 is configured.

The second case 57 is a base made of a metal such as an aluminum alloy, for example, and two through holes for guiding the light emitted from the wavelength conversion element 130 to the first photodetector 25 and the second photodetector 26 are formed in addition to the through holes of the fixed case 50.

The printed circuit board 62 is connected to the semiconductor light emitting device 10 and fixed to the second case 57 on the opposite side of the surface where the wavelength conversion element 130 is disposed.

The light source device 104 further includes the first filter 23, the second filter 24, and the cover members 51 and 61 on the surface of the second case 57 opposite to the surface to which the printed circuit board 62 is fixed.

The cover member 61 is made of a transparent material such as transparent glass. The cover member 61 is held by the cover member 51 made of a metal or the like, and is fixed to the second case 57 so as to cover the wavelength conversion element 130, the first filter 23, and the second filter 24.

The cover member 61 also has a function of guiding a part of the light emitted 95 from the wavelength conversion element 130 to the first photodetector 25 and the second photodetector 26. The action of the cover member 61 and the like on the emitted light 95 will be described below.

The excitation light 81 emitted from the semiconductor light-emitting device 10 is condensed by the condensing optical system 20 and then irradiated to the wavelength conversion element 130. A part of the light 95 emitted from the wavelength conversion element 130 is reflected when passing through the cover member 61, and enters the first filter 23 and the second filter 24. At this time, the light 95 emitted toward the first photodetector 25 enters the first filter 23. The light 95 emitted toward the second photodetector 26 enters the second filter 24.

In this configuration, the light guided to the first photodetector 25 and the second photodetector 26 is photoelectrically converted and then input to a microcontroller not shown, and this operation is similar to the light source device according to the other embodiments.

As described above, according to the structure of the light source device 104 according to the present embodiment, a light source device having a desired function can be easily realized.

(modification of example 8)

Next, a light source device according to a modification of embodiment 8 will be described. The light source device according to this modification example is provided with the first photodetector 25 similarly to the light source device 104 according to embodiment 8, but the arrangement of the first photodetector 25 and the like are different from the light source device 104 according to embodiment 8. Hereinafter, the light source device according to the present modification will be described with reference to the drawings, focusing on differences from the light source device 104 according to embodiment 8.

Fig. 37 is a schematic cross-sectional view showing the structure and function of the light source device 104A according to the present modification. Fig. 38 is a schematic cross-sectional view showing a specific configuration of the light source device 104A according to the present modification when the light projecting member 120 is further attached.

As shown in fig. 37, the light source device 104A according to the present modification includes the semiconductor light emitting device 10 and the wavelength conversion element 130. The light source device 104A further includes a case 50 for fixing the semiconductor light emitting device 10 and the wavelength conversion element 130, a second case for fixing the case 50, the printed circuit board 62, and the first photodetector 25.

In the light source device 104A according to the present modification, similar to modification 2 and modification 8 of embodiment 2 and modification 4, different phosphor materials are used for the first wavelength conversion portion 35 and the second wavelength conversion portion 36 of the wavelength conversion element 130. The support member 32 of the wavelength conversion element 130 is made of a material transparent to the propagation light 82, and the propagation light 82 enters from the support member 32 side of the wavelength conversion element 130.

In this modification, the first photodetector 25 is fixed to the semiconductor light emitting device 10.

In the semiconductor light emitting device 10 according to the present modification, the leads 13c (not shown) and 13d are mounted on the base of the package 13 in addition to the leads 13a and 13 b. The semiconductor light emitting element 11 and the first photodetector 25 are fixed to the package 13. In the semiconductor light emitting device 10 including the semiconductor light emitting element 11 and the first photodetector 25, the semiconductor light emitting element 11 is electrically connected to the leads 13a and 13 b. First photodetector 25 is electrically connected to pins 13c and 13d.

In the light source device 104A, as described above, the housing 50 is fixed to the second housing 57. The printed circuit board 62 on which the microcontroller 65 and the connector 67 are mounted is electrically connected to the pins 13a, 13b, 13c, and 13d of the semiconductor light emitting device 10, and is fixed to the second case 57.

Excitation light 81 emitted from the optical waveguide 11a formed in the semiconductor light emitting element 11 is irradiated to the wavelength conversion element 130 by the condensing optical system 20. The reflection member 31 irradiates the first wavelength converting region 35 and the second wavelength converting region 36. At this time, the reflecting member 31 passes light having the same wavelength as the excitation light 81, and reflects light generated in the first wavelength converting region 35 and the second wavelength converting region 36. Therefore, the reflecting member 31 has the same function as the first filter 23.

In this configuration, the light guided to the first photodetector 25 is photoelectrically converted and then input to a microcontroller not shown, and this operation is similar to the light source device according to the other embodiments.

As shown in fig. 38, the light projecting member 120 may be attached to the light source device 104A. In the example shown in fig. 38, a light projecting member 120, which is a parabolic mirror, for example, is mounted to the light source device 104A shown in fig. 37. Here, a screw hole 57a is formed in a surface of the second case 57 on a side close to the wavelength conversion element 130. The light projecting member 120 can be easily fixed to the light source device 104A by using the screw holes 57a. In the light projecting device including the light source device 104A and the light projecting member 120, the light emissions 91 and 92 constituting the light emission 95 emitted from the light source device 104A are emitted as the light emissions 91b and 92b traveling substantially parallel to each other in the light projecting member 120. That is, the projection light 96 having good directivity can be emitted from the light projecting device.

As described above, according to the structure of the light source device 104A according to the present embodiment, the light source device 104A having a desired function can be easily realized.

(other modifications, etc.)

The light source device and the lighting device according to the present disclosure have been described above with reference to the embodiments, but the present disclosure is not limited to the embodiments.

For example, the above embodiments and their modifications show a configuration using two wavelength converting regions, but three or more types of wavelength converting regions may be used. Accordingly, the degree of freedom in designing the wavelength distribution of the emitted light can be further improved.

In the above-described embodiments and modifications thereof, the description surrounding the first wavelength converting region 35 is not limited to a configuration in which the first wavelength converting region is disposed without interruption over the entire periphery thereof. It is sufficient to arrange at least half of the total circumference.

The present invention also includes a form in which various modifications and changes that will occur to those skilled in the art are made to the respective embodiments, and a form in which the constituent elements and functions of the respective embodiments are arbitrarily combined within a range not departing from the spirit of the present invention.

In the light source device and the lighting device of the present disclosure, as described above, the utilization efficiency of the excitation light is high, and the luminance distribution and the color distribution around the dot image can be freely designed. Accordingly, the light source device and the lighting device of the present disclosure are applicable to various light source devices and lighting devices such as a headlight for a vehicle, a spotlight light source, and the like for an automobile, a railway vehicle, a bicycle, and the like.

Claims

1. A light source device is provided with:

a semiconductor light emitting device that emits coherent excitation light;

a wavelength conversion unit that performs wavelength conversion on the excitation light to generate fluorescence, and scatters the excitation light to generate scattered light, thereby emitting emission light including the fluorescence and the scattered light;

a first photodetector that detects the intensity of the scattered light;

a second photodetector that detects the intensity of the fluorescence; and

a base having a through hole in the center,

the semiconductor light emitting device includes:

a semiconductor light emitting element that emits the excitation light;

a package body for fixing the semiconductor light emitting element;

a metal can fixed to the package and covering the semiconductor light emitting element; and

a condensing optical system condensing the excitation light,

the semiconductor light emitting device is fixed on one surface of the base connected to the through hole,

the wavelength conversion part is fixed on the other surface of the base connected to the through hole,

the condensing optical system is fixed to the metal can.

2. A light source device is provided with:

a semiconductor light emitting device that emits coherent excitation light;

a first photodetector that detects the intensity of the scattered light;

a second photodetector that detects the intensity of the fluorescence; and

a cover member covering the wavelength conversion portion,

the wavelength conversion part has a first surface and a second surface opposite to the first surface,

the excitation light is incident on the second face,

the emitted light has: a first light emitted from the first surface and a second light emitted from the second surface,

the first emitted light includes output light,

the output light is emitted from the light source device to the outside,

the first emitted light includes the scattered light incident on the first photodetector and the fluorescence incident on the second photodetector,

the cover member includes: and an optical member that guides the scattered light and the fluorescence to the first photodetector and the second photodetector.

3. A light source device is provided with:

a semiconductor light emitting device that emits coherent excitation light;

a first photodetector that detects the intensity of the scattered light;

a second photodetector that detects the intensity of the fluorescence; and

a reflecting member that guides the scattered light and the fluorescence to the first photodetector and the second photodetector,

the wavelength converting region has a first face,

the excitation light is incident on the first face of the wavelength converting region,

the outgoing light has a first outgoing light outgoing from the first face,

the first emitted light includes output light,

the output light is emitted from the light source device to the outside,

the reflection member is configured to receive a portion of the first light emitted from the light source device, the portion not being emitted to the outside.

4. A light source device according to any one of claims 1 to 3, wherein,

the light source device further includes a first filter,

a portion of the scattered light is incident to the first photodetector via the first filter.

5. A light source device according to any one of claims 1 to 3, wherein,

The light source device further comprises a second filter,

a portion of the fluorescence is incident to the second photodetector via the second filter.

6. A light source device according to any one of claims 1 to 3, wherein,

the light source device further includes: and a condensing member that condenses the excitation light.

7. The light source device according to claim 1, wherein,

the excitation light is incident on the second face,

the first emitted light is emitted from the light source device,

the first emitted light includes the scattered light incident on the first photodetector and the fluorescence incident on the second photodetector.

8. A light source device according to any one of claims 1 to 3, wherein,

the first photodetector and the second photodetector are configured on the same printed circuit board.

9. A light source device according to any one of claims 1 to 3, wherein,

the light source device further includes: and a third photodetector for detecting the intensity of the excitation light.

10. The light source device according to claim 9, wherein,

the first photodetector, the second photodetector, and the third photodetector are disposed on the same printed circuit board.

11. A light source device according to any one of claims 1 to 3, wherein,

a ratio of the amounts of scattered light and fluorescent light from the wavelength conversion section is detected based on signals from the first photodetector and the second photodetector.

12. The light source device according to claim 9, wherein,

a ratio of the amounts of the fluorescence light and the excitation light from the wavelength conversion section is detected based on signals from the second photodetector and the third photodetector.

13. The light source device according to claim 11, wherein,

when the ratio is not within a predetermined range, the power applied to the light source device is stopped.

14. The light source device according to claim 12, wherein,

15. A lighting device comprising the light source device according to any one of claims 1 to 13.